Structural, Merchanical Thermodynamic, and Optical Properties OF Condensed Matter

Indicators of internal structural states for metallic glasses: Local order, free volume, and configurational potential energy

Y. Q. Cheng and E. Ma
The structural states of metallic glasses (MGs) have been described previously using concepts such as free volume and configurational potential energy. Here we discuss the inadequacy of these indicators by examining a CuZrAl MG model experiencing different cooling and relaxation history. The results ... [Appl. Phys. Lett. 93, 051910 (2008)] published Thu Aug 7, 2008.

Impact of fragility on enthalpy relaxation in glass

John C. Mauro and Roger J. Loucks
The macroscopic properties of a glass are continually relaxing toward their equilibrium supercooled liquid values. Experimentally, the shape of the relaxation function in a glass is known to depend on the fragility of the supercooled liquid. In this paper, we investigate the impact of fragility on t ... [Phys. Rev. E 78, 021502 (2008)] published Thu Aug 7, 2008.

Reentrant isotropic-nematic phase transition

M. Simoes, M. Pazetti, S. M. Domiciano, D. A. Oliveira, and A. J. Palangana
This work aims at a geometrical semimicroscopic model to study the reentrant isotropic-nematic phase transition. It will be assumed that the micellar change of shape in lyotropics can be understood as the deformation of an ellipsoid which is assumed to have the idealized form of a micelle. It will b ... [Phys. Rev. E 78, 022702 (2008)] published Thu Aug 7, 2008.

Three-dimensional percolation modeling of self-healing composites

Alexander Dementsov and Vladimir Privman
We study the self-healing process of materials with embedded glue-carrying cells, in the regime of the onset of the initial fatigue. Three-dimensional numerical simulations within the percolation-model approach are reported. The main numerical challenge taken up in the present work has been to exten ... [Phys. Rev. E 78, 021104 (2008)] published Thu Aug 7, 2008.

Fluids of spherical molecules with dipolarlike nonuniform adhesion: An analytically solvable anisotropic model

Domenico Gazzillo, Riccardo Fantoni, and Achille Giacometti
We consider an anisotropic version of Baxter's model of sticky hard spheres, where a nonuniform adhesion is implemented by adding, to an isotropic surface attraction, an appropriate dipolar sticky correction (positive or negative, depending on the mutual orientation of the molecules). The resulting ... [Phys. Rev. E 78, 021201 (2008)] published Thu Aug 7, 2008.

Quantitative theory of a relaxation function in a glass-forming system

Edan Lerner and Itamar Procaccia
We present a quantitative theory for a relaxation function in a simple glass-forming model (binary mixture of particles with different interaction parameters). It is shown that the slowing down is caused by the competition between locally favored regions (clusters) that are long-lived but each of wh ... [Phys. Rev. E 78, 020501 (2008)] published Thu Aug 7, 2008.

Influence of Mo on the Fe:Mo:C nanocatalyst thermodynamics for single-walled carbon nanotube growth

Stefano Curtarolo, Neha Awasthi, Wahyu Setyawan, Aiqin Jiang, Kim Bolton et al.
We explore the role of Mo in Fe:Mo nanocatalyst thermodynamics for low-temperature chemical-vapor deposition growth of single-walled carbon nanotubes (SWCNTs). By using the size-pressure approximation and ab initio modeling, we prove that for both Fe-rich (~80% Fe or more) and Mo-rich (~50% Mo or mo ... [Phys. Rev. B 78, 054105 (2008)] published Thu Aug 7, 2008.

Whispering-gallery mode resonators: Surface enhanced Raman scattering without plasmons

Logan K. Ausman and George C. Schatz
Calculations based on the Mie theory are performed to determine the locally enhanced electric fields due to whispering-gallery mode resonances for dielectric microspheres, with emphasis on electromagnetic hot spots that are located along the wavevector direction on the surface of the sphere. The loc ... [J. Chem. Phys. 129, 054704 (2008)] published Thu Aug 7, 2008.

Nonuniform liquid-crystalline phases of parallel hard rod-shaped particles: From ellipsoids to cylinders

Y. Martinez-Raton and E. Velasco
In this article we consider systems of parallel hard superellipsoids, which can be viewed as a possible interpolation between ellipsoids of revolution and cylinders. Superellipsoids are characterized by an aspect ratio and an exponent alpha (shape parameter) which takes care of the geometry, with al ... [J. Chem. Phys. 129, 054907 (2008)] published Thu Aug 7, 2008.

Structure and pressure inside Xe nanoparticles embedded in Al

Konstantin Iakoubovskii, Kazutaka Mitsuishi, and Kazuo Furuya
Crystalline and amorphous xenon nanoparticles were produced in aluminum by Xe ion implantation and were characterized with high-resolution electron microscopy combined with electron energy loss (EEL) spectroscopy. Unusual distributions of the aspect ratio and of the diameter of the crystalline parti ... [Phys. Rev. B 78, 064105 (2008)] published Thu Aug 7, 2008.

Nucleation and growth of a quasicrystalline monolayer: Bi adsorption on the fivefold surface of i-Al[sub 70]Pd[sub 21]Mn[sub 9]

J. A. Smerdon, J. K. Parle, L. H. Wearing, T. A. Lograsso, A. R. Ross et al.
Scanning tunneling microscopy has been used to study the formation of a Bi monolayer deposited on the fivefold surface of i-AlPdMn. Upon deposition of low submonolayer coverages, the nucleation of pentagonal clusters of Bi adatoms of edge length 4.9 A is observed. The clusters have a common orienta ... [Phys. Rev. B 78, 075407 (2008)] published Thu Aug 7, 2008.

Motion-dependent magnetic properties of excitons in CdTe

L. C. Smith, J. J. Davies, D. Wolverson, S. Crampin, R. T. Cox et al.
Very large changes in the Zeeman splittings and in the diamagnetism of excitons as they acquire kinetic energy in wide quantum wells of CdTe are reported. The changes are found to be functions of the translational wave vector K of the exciton in the growth direction of the well, irrespective of the ... [Phys. Rev. B 78, 085204 (2008)] published Thu Aug 7, 2008.

Optimization of metal dispersion in doped graphitic materials for hydrogen storage

Gyubong Kim, Seung-Hoon Jhi, Noejung Park, Steven G. Louie, and Marvin L. Cohen
The noncovalent hydrogen binding on transition-metal atoms dispersed on carbon clusters and graphene is studied with the use of the pseudopotential density-functional method. It is found that the presence of acceptorlike states in the absorbents is essential for enhancing the metal adsorption streng ... [Phys. Rev. B 78, 085408 (2008)] published Thu Aug 7, 2008.

Erratum: X-ray determination of strain and damage distributions in ion-implanted layers

V. S. Speriosu, H. L. Glass, and T. Kobayashi
... [Appl. Phys. Lett. 35, 947 (2008)] published Thu Aug 7, 2008.

Observation of semiconductor-semimetal transition in InAs-GaSb superlattices

L. L. Chang, N. Kawai, G. A. Sai-Halasz, R. Ludeke, and L. Esaki
The semiconductor-semimetal transition in InAs-GaSb superlattices is observed at a layer thickness in the vicinity of 100 A. The transition manifests itself in an increase in the measured carrier concentration as a result of electron transfer from GaSb to InAs when ground subbands of electrons and h ... [Appl. Phys. Lett. 35, 939 (2008)] published Thu Aug 7, 2008.

Photoluminescence from hydrogenated ion-implanted crystalline silicon

J. I. Pankove and C. P. Wu
Ion-implanted crystalline silicon annealed in atomic hydrogen photoluminesces at 0.990.01 eV in a band having a spectral width of 0.1 eV FWHM. The emitted spectrum does not depend on the chemical nature of the implanted ion (Al, As, D, F, H, Ne, P, Si); however, when the surface is amorphized, a spe ... [Appl. Phys. Lett. 35, 937 (2008)] published Thu Aug 7, 2008.

Luminescent p-GaAs grown by zinc ion doped MBE

J. C. Bean and R. Dingle
Low-energy zinc ions have been incorporated in growing MBE GaAs layers producing heavily doped p-type material. As-grown layers retain a substantial amount of radiation damage as indicated by the absence of photoluminescence and low hole mobilities. A postgrowth anneal yields layers with low-tempera ... [Appl. Phys. Lett. 35, 925 (2008)] published Thu Aug 7, 2008.

The emission spectrum from planar-channeled electrons

R. H. Pantell and R. L. Swent
Planar-channeled electrons radiate electromagnetic energy with sharp peaks in the emission spectrum. A model is developed to predict the locations of these peaks, which are shown to correlate well with experimental observations. A by-product of the model is that it provides a sensitive method for de ... [Appl. Phys. Lett. 35, 910 (2008)] published Thu Aug 7, 2008.

Pulsed electron beam induced recrystallization and damage in GaAs

J. L. Tandon, I. Golecki, M-A. Nicolet, D. K. Sadana, and J. Washburn
Single-pulse electron-beam irradiations of 300-keV 10Kr/cm or 300-keV 3 x 10 Se/cm implanted layers in unencapsulated GaAs are studied as a function of the electron beam fluence. The electron beam pulse had a mean electron energy of ~=20 keV and a time duration of ?10 s. Analyses by means of MeV He ... [Appl. Phys. Lett. 35, 867 (2008)] published Thu Aug 7, 2008.

High current density Ga[sup + ] implantations into Si

R. R. Hart, C. L. Anderson, H. L. Dunlap, R. L. Seliger, and V. Wang
The lattice disorder produced in Si by a 59-keV Ga ion beam focused to a diameter of 1200 A and having a current density of 1.2 A/cm was compared to that produced by broad area implantations of 59-keV Ga at a current density of 0.4 [mu]A/cm. Based on 140-keV proton backscattering, the disorder produ ... [Appl. Phys. Lett. 35, 865 (2008)] published Thu Aug 7, 2008.

Studies of the Si-SiO[sub 2] interface by MeV ion channeling

N. W. Cheung, L. C. Feldman, P. J. Silverman, and I. Stensgaard
By performing backscattering-channeling measurements in two different geometries on thin Si crystals thermally oxidized at 800 degrees C, we have obtained upper and lower limits of the number of reconstructed Si layers at the Si-SiO interface. The results indicate an abrupt Si-SiO interface with on ... [Appl. Phys. Lett. 35, 859 (2008)] published Thu Aug 7, 2008.

Theory of elastic properties of composite materials

James G. Berryman
A new method of estimating effective macroscopic elastic constants for microscopically inhomogeneous materials is formulated using elastic-wave scattering theory. The self-consistent medium is determined by the condition that the scattered long-wavelength displacement field must vanish on the averag ... [Appl. Phys. Lett. 35, 856 (2008)] published Thu Aug 7, 2008.

High-resolution optoacoustic spectroscopy of rare-earth oxide powders

A. C. Tam and C. K. N. Patel
We report high-resolution absorption spectroscopy of powdered microsamples using a pulsed laser and a gated optoacoustic detection technique. Our method is simple, sensitive, and easily adaptable for cryogenic cooling of the sample. Quantitative data for HoO, DyO, and ErO powdered crystals are obtai ... [Appl. Phys. Lett. 35, 843 (2008)] published Thu Aug 7, 2008.

The effects of neutron irradiation on a superconducting metallic glass

E. A. Kramer, W. L. Johnson, and C. Cline
The effects of fast neutron irradiation on a superconducting metallic glass (MoRu)B have been studied. Following irradiation to a total fluence of 10 n/cm, T increases from 6.05 to 6.19 K, and the width of the transition decreases sharply. The density of the material decreases by 1.5%, and the x-ray ... [Appl. Phys. Lett. 35, 815 (2008)] published Thu Aug 7, 2008.

Efficient shallow-homojunction GaAs solar cells by molecular beam epitaxy

John C. C. Fan, A. R. Calawa, Ralph L. Chapman, and George W. Turner
Conversion efficiencies up to 16% at AM1 have been obtained for molecular beam epitaxy (MBE) GaAs solar cells utilizing a shallow-homojunction n/p/p structure without a GaAlAs window. The n, p, and p GaAs layers were all grown by MBE on single-crystal p GaAs substrates. Cell metallization was perfor ... [Appl. Phys. Lett. 35, 804 (2008)] published Thu Aug 7, 2008.

The lateral effect of oxidation on boron diffusion in silicon

A. M. Lin, R. W. Dutton, and D. A. Antoniadis
It is found that oxidation of silicon not only enhances the diffusion of the dopants in the regions under oxidized surface but also in the adjacent unoxidized regions. The diffusivity of boron in the narrow unoxidized regions is enhanced by the oxidation with an enhancement decreasing rapidly with t ... [Appl. Phys. Lett. 35, 799 (2008)] published Thu Aug 7, 2008.

The influence of annealing ambient on the shrinkage kinetics of oxidation-induced stacking faults in silicon

Cor L. Claeys, Gilbert J. Declerck, and Roger J. Van Overstraeten
The shrinkage behavior of oxidation-induced stacking faults (OSF's) during an annealing in nitrogen, argon, and hydrogen is studied as a function of both annealing temperature and time. Independent of the used gas atmosphere, the OSF shrinkage rate is characterized by an activation energy of 4.9 eV. ... [Appl. Phys. Lett. 35, 797 (2008)] published Thu Aug 7, 2008.

Vapor-phase epitaxial growth of InGaAs lattice matched to (100) InP for photodiode application

S. B. Hyder, R. R. Saxena, S. H. Chiao, and R. Yeats
Vapor-phase epitaxial growth of InGaAs lattice matched to (100) -oriented InP substrates is described, and the performance of photodiodes fabricated from this material is presented. Gas-flow conditions for lattice-matched growth with various Ga-CHl flows were established for growth using the hydride ... [Appl. Phys. Lett. 35, 787 (2008)] published Thu Aug 7, 2008.

Imaging of dislocations in InP using transmission cathodoluminescence

A. K. Chin, S. Mahajan, and A. A. Ballman
We present an exact one-to-one correspondence between grown-in dislocations revealed as etch pits and dark spots observed on transmission cathodoluminescence images of InP. This correspondence has been demonstrated for heavily tellurium- and sulfur-doped InP. This is the first time that dislocations ... [Appl. Phys. Lett. 35, 784 (2008)] published Thu Aug 7, 2008.

Discovery of a new reversible electrochromic effect

P. Pfluger, H. U. Kunzi, and H.-J. Guntherodt
A new electrochromic effect based on the electrochemical intercalation of graphite is described. This effect seems to have a promising potential for applications in display devices. ... [Appl. Phys. Lett. 35, 771 (2008)] published Thu Aug 7, 2008.

Room temperature instability of electron induced defects in n-type silicon containing germanium

A. O. Evwaraye
n-type silicon containing germanium was irradiated with a 1.5-MeV electron beam at 300 K. An electron trap E3(E0.35 eV), not observed in n-type silicon without germanium, is unstable at room temperature. Annealing studies show that the annealing kinetics is first order; an activation energy for ther ... [Appl. Phys. Lett. 35, 769 (2008)] published Thu Aug 7, 2008.

Impedance-match experiments using laser-driven shock waves

L. R. Veeser, J. C. Solem, and A. J. Lieber
A high-energy laser pulse has been used to drive a shock wave into a foil target. Pressures of 0.3 TPa in aluminum and 0.6 TPa in a gold overlay were inferred from simultaneous measurements of the shock velocities. The techniques will be useful in determining high-pressure equation-of-state paramete ... [Appl. Phys. Lett. 35, 761 (2008)] published Thu Aug 7, 2008.

Optoacoustic phase angle measurement for probing a metal

G. Busse
It is shown that using optoacoustic phase angle scanning rather than amplitude scanning enables precise measurements of subsurface structure in metal. For some applications the method can be an alternative to x-ray imaging. ... [Appl. Phys. Lett. 35, 759 (2008)] published Thu Aug 7, 2008.

Acoustic microscopy of polymer materials

Robert G. Wilson and Paul A. Tucker
Reflection acoustic microscopy has been used to study polymer materials. Acoustic micrographs of polypropylene spherulites show branching and irregular growth of radial fibrils and a more three-dimensional interpenetrant nature of the impinging spherulites than does light microscopy. Acoustic microg ... [Appl. Phys. Lett. 35, 755 (2008)] published Thu Aug 7, 2008.

Active pulse shaping in the picosecond domain

J. Agostinelli, G. Mourou, and C. W. Gabel
Active pulse shaping in the picosecond domain is reported using a fast Pockels cell controlled by an optically driven GaAs electrical switch. The center is sliced out of a long optical pulse, yielding a 70-psec FWHM pulse with 40-psec rise and fall times. ... [Appl. Phys. Lett. 35, 731 (2008)] published Thu Aug 7, 2008.

Thermally induced accumulation of silicon on palladium silicide surfaces as studied by Auger electron spectroscopy

K. Oura, S. Okada, and T. Hanawa
A clean surface of a palladium silicide grown on a Si(111) plane has been studied by Auger electron spectroscopy. Heat treatment of the silicide in the temperature range 250600 degrees C causes the accumulation of a thin layer of elementary Si over its surface. The accumulated thickness has been es ... [Appl. Phys. Lett. 35, 705 (2008)] published Thu Aug 7, 2008.

Self-diffusion in silicon as probed by the ( p,gamma) resonance broadening method

J. Hirvonen and A. Anttila
The self-diffusion preexponential factor D=8.0 cm/s and activation energy Q=4.1 eV for intrinsic silicon have been determined with the ( p,gamma) resonance broadening method in the temperature region 9001100 degrees C, in a first application of this method to self-diffusion measurements. Its suitab ... [Appl. Phys. Lett. 35, 703 (2008)] published Thu Aug 7, 2008.

Implantation of shallow impurities in Cr-doped semi-insulating GaAs

P. N. Favennec and H. L'Haridon
Zinc and selenium implantations have been performed in Cr-doped semi-insulating GaAs. We show that all zinc and selenium implanted impurities are electrically active after annealing at 900 degrees C. But, in addition to the implantation distribution, there is a distribution induced by the chromium ... [Appl. Phys. Lett. 35, 699 (2008)] published Thu Aug 7, 2008.

The growth of a GaAs VPE layer with an abrupt doping profile

J. Komeno and S. Ohkawa
A technique for achieving the growth of GaAs VPE layers with a highly abrupt doping profile is described. With this technique, the steepness of doping profile is remarkably improved and typical interface widths for the drop in carrier concentration from 1 x 10 to 1 x 10 cm are 1000 A. This technique ... [Appl. Phys. Lett. 35, 693 (2008)] published Thu Aug 7, 2008.

Electric field induced bend-undulation instability in a ferroelectric smectic C

Noel A. Clark
A new electric field induced mechanical instability of a single domain ferroelectric smectic C liquid is proposed. Threshold conditions and small and large field limits are discussed. ... [Appl. Phys. Lett. 35, 688 (2008)] published Thu Aug 7, 2008.

A new thin-film electroluminescent material---ZnF[sub 2] : Mn

D. C. Morton and F. E. Williams
Both ac and dc orange (580 nm) electroluminescence (EL) are reported for thin films of ZnF : Mn sandwiched between SiO semi-insulating films. All layers are formed by vacuum evaporation and no postdeposition annealing is required. Unique power input and efficiency-vs-frequency characteristics are ob ... [Appl. Phys. Lett. 35, 671 (2008)] published Thu Aug 7, 2008.

The scope of effective medium theory for fine metal particle solar absorbers

G. B. Smith
The treatment of an array of small metal particles as a continuous effective medium is shown to be possible for visible and near infrared frequencies at much larger particle sizes and separations than often supposed. Specific upper limits are evaluated for chromium. Results are based on the strongly ... [Appl. Phys. Lett. 35, 668 (2008)] published Thu Aug 7, 2008.

Detection of ferromagnetic resonance by photoacoustic effect

O. A. Cleves Nunes, A.M.M. Monteiro, and K. Skeff Neto
By exploring the simple periodic heat-flux principle of the photoacoustic cell we propose and demonstrate experimentally the usefulness of the photoacoustic cell for studying the ferromagnetic resonance. An interesting feature of this technique is that it offers special advantages over conventional ... [Appl. Phys. Lett. 35, 656 (2008)] published Thu Aug 7, 2008.

Erratum: Buried-grid fabrication by silicon liquid-phase epitaxy

B. Jayant Baliga
... [Appl. Phys. Lett. 35, 647 (2008)] published Thu Aug 7, 2008.

Erratum: Long-term Hall-type conversion by vacancy diffusion in Hg[sub 1 - x]Cd[sub x]Te at room temperature

G. Nimtz, B. Schlicht, and R. Dornhaus
... [Appl. Phys. Lett. 35, 647 (2008)] published Thu Aug 7, 2008.

cw Ar[sup + ] laser annealing of optically active impurities in nitrogen-implanted Al[sub x]Ga[sub 1 - x]As (x=0.58)

Yunosuke Makita, Masaki Yokota, Hidetoshi Nojiri, Toshio Tsurushima, Hisao Tanoue et al.
Laser annealing of nitrogen implanted AlGaAs was carried out by using an Ar laser. A reliable and well-controlled annealing was performed with threshold power density of the order of 10 W/cm. Photoluminescence (PL) characteristics show that laser annealing is superior to thermal annealing in terms o ... [Appl. Phys. Lett. 35, 633 (2008)] published Thu Aug 7, 2008.

Pulse electron annealing of ion-implanted InP

D. Eirug Davies, J. P. Lorenzo, T. G. Ryan, and J. J. Fitzgerald
Pulsed electron beam annealing has been used to activate high-dose silicon implants in InP. Peak concentrations >~ 10 cm are obtained without any appreciable carrier freezeout on cooling to 78 degrees K. Such activation is comparable to that obtained on thermal annealing and is seen on samples impl ... [Appl. Phys. Lett. 35, 631 (2008)] published Thu Aug 7, 2008.

Dynamic behavior of mode-locked Nd : YAG laser annealing in ion-implanted Si, GaAs, and GaP

Kouichi Murakami, Kenji Gamo, Susumu Namba, Mitsuo Kawabe, and Yoshinobu Aoyagi
By measuring the time-dependent optical reflectivity, we have investigated the dynamic behavior of annealing with the 30-psec pulse train of a mode-locked Nd : YAG laser. It was first observed that at narrow ranges of high laser energy density, the reflectivity of implanted Si and GaAs increases slo ... [Appl. Phys. Lett. 35, 628 (2008)] published Thu Aug 7, 2008.

Photoluminescence of gallium arsenide encapsulated with aluminum nitride and silicon nitride

Hulya Birey, Sung-Jae Pak, and J. R. Sites
Aluminum nitride and silicon nitride films were deposited on lightly doped n-type GaAs : Si by low-energy ion beam sputtering. Mechanically, the films were stable at annealing temperatures above 900 degrees C. In contrast to bare GaAs and previously reported encapsulation with SiN, where the 1.36-e ... [Appl. Phys. Lett. 35, 623 (2008)] published Thu Aug 7, 2008.

Short-channel MOS FET's fabricated by self-aligned ion implantation and laser annealing

M. Koyanagi, H. Tamura, M. Miyao, N. Hashimoto, and T. Tokuyama
Short-channel MOS FET's are successfully fabricated using Q-switched ruby laser irradiation on As-implanted sources and drains. Implantation and laser irradiation are both self-aligned by the polysilicon gate electrodes. The threshold-voltagevschannel-length relation is improved as a result of the e ... [Appl. Phys. Lett. 35, 621 (2008)] published Thu Aug 7, 2008.

Substrate temperature limits for epitaxy of InP by MBE

M. T. Norris and C. R. Stanley
The temperature range within which epitaxial unintentionally doped InP can be deposited from In and P beams by MBE on to (100) InP substrates has been determined to be 100405 degrees C. Above 410 degrees C whisker growth from In droplets via a vapor-liquid-solid process occurs; below 95 degrees C ... [Appl. Phys. Lett. 35, 617 (2008)] published Thu Aug 7, 2008.

Alloying of Au layers and redistribution of Cr in GaAs

T. J. Magee, J. Peng, J. D. Hong, V. R. Deline, and C. A. Evans, Jr.
Alloying of Au films on Cr-doped GaAs substrates and Sn-doped LPE layers grown on semi-insulating substrates has been investigated by TEM and SIMS profiling. Annealing at 350 degrees C for variable periods was found to produce rapid outdiffusion of Cr into regions of near-surface damage induced by ... [Appl. Phys. Lett. 35, 615 (2008)] published Thu Aug 7, 2008.

Methods for minimizing silicon regrowth in aluminum films

Arthur J. Learn and R. S. Nowicki
The transport of polycrystalline silicon into an overlying aluminum film and silicon regrowth in the metal medium under heating at 500 degrees C was examined as a function of doping level and grain size of the silicon. Such regrowth was eliminated through phosphorus doping and was substantially red ... [Appl. Phys. Lett. 35, 611 (2008)] published Thu Aug 7, 2008.

Thin films of LiNbO[sub 3], doped with Na[sup + ] and Co[sup 2 + ]+Zr[sup 4 + ], grown by liquid-phase epitaxy

R.R. Neurgaonkar, M.H. Kalisher, E. J. Staples, and T. C. Lim
LiNbO thin films doped with Na and Co+ Zr have been obtained by the liquid-phase epitaxial (LPE) technique from LiO-VO flux. X-ray diffraction studies indicated that the films had a high single crystallinity with good epitaxy. The Na and Co +Zr doped LiNbO films showed a reduction in the temperature ... [Appl. Phys. Lett. 35, 606 (2008)] published Thu Aug 7, 2008.

Vapor-phase epitaxial In[sub x]Ga[sub 1 - x]As on (100), (111)A, and (111)B InP substrates

Hiroshi Kanbe, Yoshiharu Yamauchi, and Nobuhiko Susa
Effects of InP substrate orientation on InGaAs vapor-phase epitaxial growth are studied. The fractional composition x of the grown layer on (100) substrate is smaller than for (111) B at identical growth temperatures and gas flow rates. The In content x decreases with increasing temperature. Growth ... [Appl. Phys. Lett. 35, 603 (2008)] published Thu Aug 7, 2008.

Electromagnetic acoustic resonance in metals and alloys

E. G. Spencer, P. H. Schmidt, and F. J. Sansalone
A technique has been developed for measuring the temperature dependence of elastic moduli of metals and alloys using electromagnetic excitation of acoustic resonance in small spheres polished optically smooth. A frequency swept marginal oscillator is used to generate and detect resonances without ph ... [Appl. Phys. Lett. 35, 593 (2008)] published Thu Aug 7, 2008.

Pulsed electron-beam annealing of selenium-implanted gallium arsenide

T. Inada, K. Tokunaga, and S. Taka
Electrical properties of selenium-implanted gallium arsenide annealed by a single shot of high-power pulsed electron beams have been investigated by differential Hall-effect and sheet-resistivity measurements. It has been shown that higher electrical activation of implanted selenium can be obtained ... [Appl. Phys. Lett. 35, 546 (2008)] published Thu Aug 7, 2008.

An additional source of photovoltage in photoconductive materials

S. J. Fonash and S. Ashok
A possible additional source of photovoltage in solar cells made on photoconductive materials is identified. Arising from suitable compositional or doping variations of the material, this excess voltage could significantly enhance the open-circuit voltage of solar cells fabricated on amorphous Si : ... [Appl. Phys. Lett. 35, 535 (2008)] published Thu Aug 7, 2008.

Solid solubility of As in Si as determined by ion implantation and cw laser annealing

A. Lietoila, J. F. Gibbons, T. J. Magee, J. Peng, and J. D. Hong
Complete electrical activity was obtained by cw laser annealing of 7 x 10 As/cm implanted into (100) Si at 100 keV. The peak concentration for these implantation conditions is 1.4 x 10/cm, both theoretically and experimentally. However, this peak concentration was found to be thermally unstable, rel ... [Appl. Phys. Lett. 35, 532 (2008)] published Thu Aug 7, 2008.

Kinetics of the thermal oxidation of WSi[sub 2]

F. Mohammadi, K. C. Saraswat, and J. D. Meindl
The thermal oxidation WSi films has been studied. Thin films of WSi were deposited by sputtering on (100) silicon and on oxidized silicon, and then oxidized in dry O and in steam atmospheres at 1000, 1100, and 1200 degrees C for times up to 30 min. In all cases the dry O oxidation resulted in films ... [Appl. Phys. Lett. 35, 529 (2008)] published Thu Aug 7, 2008.

Bright green electroluminescence in thin-film ZnS : TbF[sub 3]

K. Okamoto and Y. Hamakawa
A bright green electroluminescent (EL) thin-film device for a flat-type display has been developed. The device is constructed by a ZnS : TbF thin-film sandwiched between two semiconductive YO layers. A typical brightness of 200 fL and a power conversion efficiency of 4 x 10 W/W, values at least seve ... [Appl. Phys. Lett. 35, 508 (2008)] published Thu Aug 7, 2008.

High-power switching with picosecond precision

G. Mourou and W. Knox
Up to 10 kV have been switched with Si and GaAs laser-activated switches. We show that in spite of the thermal instability shortcoming experienced in Si, quasi-dc bias operation can be utilized in a manner which relaxes stringent synchronization requirements. In the case of GaAs the thermal instabil ... [Appl. Phys. Lett. 35, 492 (2008)] published Thu Aug 7, 2008.

Photoluminescence of undoped (100) InP homoepitaxial films grown by molecular beam epitaxy

Yuichi Kawamura, Mutsuo Ikeda, Hajime Asahi, and Hiroshi Okamoto
A comparative study is given of the photoluminescence properties between undoped (100) InP homoepitaxial MBE and LPE films and bulk crystals. All of the samples show two peaks; one is a near band-edge emission at 1.41 eV with a small shoulder and the other is at about 1.13 eV. It is shown that the M ... [Appl. Phys. Lett. 35, 481 (2008)] published Thu Aug 7, 2008.

Flexible GaAs ribbons

W. Tantraporn
Thin GaAs ribbons from Ga-AsCl-H epitaxy are flexible. The rapid growth occurs along a <112-bar> vector. The thin edges are {110}-type planes while the flat surfaces appear to be {111}. A ribbon of dimensions 2 x 0.1 x 0.002 cm can be bent to 1 cm diameter without breakage. ... [Appl. Phys. Lett. 35, 449 (2008)] published Thu Aug 7, 2008.

Electrical and structural characteristics of laser-induced epitaxial layers in silicon

R. T. Young, J. Narayan, and R. F. Wood
We have used pulsed-laser radiation to grow homoepitaxial p-n junctions in silicon. Doped amorphous silicon was deposited on (100) and (111) silicon substrates and annealed with a Q-switched ruby laser. By this technique, perfect epitaxial layers with good electrical characteristics and controlled d ... [Appl. Phys. Lett. 35, 447 (2008)] published Thu Aug 7, 2008.

Variable-temperature photoacoustic effect: Application to phase transition

C. Pichon, M. Le Liboux, D. Fournier, and A. C. Boccara
A low-temperature-adapted photoacoustic cell using an electret microphone and a MOSFET preamplifier is described. This cell can operate between 5 and 300 K in a gas-flow cryostat. By way of illustration, it is used here to perform a new kind of photoacoustic measurement, i.e., to study the specific- ... [Appl. Phys. Lett. 35, 435 (2008)] published Thu Aug 7, 2008.

Efficient generation of low-energy positrons

Allen P. Mills, Jr.
Positrons with a nearly thermal-energy distribution can be generated by moderating the beta-decay spectrum of a radioactive beta source. The efficiency epsilon of this process is improved substantially by using a clean single-crystal Cu moderator which has been activated by a one-third monolayer of ... [Appl. Phys. Lett. 35, 427 (2008)] published Thu Aug 7, 2008.

Laser-induced metal-to-semiconductor phase transition in mixed Al-Sb films

R. Andrew, M. Ledezma, M. Lovato, M. Wautelet, and L. D. Laude
Metallic films consisting of overlapping polycrystalline layers of, alternatively, Al or Sb atoms in overall equal proportions are irradiated at 300 degrees K with 80-mJ/cm microsecond dye laser pulses of 2-eV photon energy. Using transmission electron microscopy, electron diffraction, optical tran ... [Appl. Phys. Lett. 35, 418 (2008)] published Thu Aug 7, 2008.

Influence of spin density in implanted Si layers on pulsed-laser annealing

K. Murakami, E. Ikawa, K. Gamo, S. Namba, Y. Akasaka et al.
In order to clarify an influence of the spin density or the optical absorption coefficient on the pulsed-laser annealing effect, we have performed systematically ion-backscattering and channeling analysis and ESR measurement as a funcion of spin densities in ion-implanted Si samples. It was found th ... [Appl. Phys. Lett. 35, 413 (2008)] published Thu Aug 7, 2008.

Comparison of dopant incorporation into polycrystalline and monocrystalline silicon

J. R. Monkowski, J. Bloem, L. J. Giling, and M. W. M. Graef
The capacitance-voltage (C-V) technique was used to compare the dopant distribution in polycrystalline silicon to that in monocrystalline silicon grown under the same conditions via chemical vapor deposition. Over a doping range extending from approximately 10 to 10 cm, the polycrystalline and monoc ... [Appl. Phys. Lett. 35, 410 (2008)] published Thu Aug 7, 2008.

Diffusion and p-type conduction of magnesium impurities in germanium

L. T. Ho
Magnesium has been introduced into germanium by the diffusion technique. After heat treatment, the room-temperature carrier concentration of the sample is of the order of 10 cm. Conversion of the sample conductivity from n type to p type indicates that magnesium behaves like a substitutional double ... [Appl. Phys. Lett. 35, 409 (2008)] published Thu Aug 7, 2008.

Differences in sodium transport in SiO[sub 2] films caused by ion and neutral-particle bombardment

Daniel V. McCaughan, C. W. White, R. A. Kushner, and D. L. Simms
The transport of impurity atoms from the surface to the SiO/Si interface of SiO films on silicon subjected to ion and neutral-particle bombardment has been found to depend critically on the charge state of the incident projectile. SiO films on silicon, intentionally contaminated with Na, have been b ... [Appl. Phys. Lett. 35, 405 (2008)] published Thu Aug 7, 2008.

Pseudoalloy behavior at interfaces; AgAu

G. K. Wertheim, C. W. Bates, Jr., J. H. Wernick, and D. N. E. Buchanan
Analysis of mixed metallic layers formed by grain-boundary diffusion shows that atoms at the interface have properties resembling those of a solid solution. Generalization of this result suggests that the sharpness of an interface cannot be defined by electronic properties to better than two atomic ... [Appl. Phys. Lett. 35, 403 (2008)] published Thu Aug 7, 2008.

Evidence of room-temperature sintering in aluminum contacts in vacuum and in oxygen

R. S. Timsit
It is found that the area of metallic contact between two aluminum surfaces grows at room temperature both in ultrahigh vacuum and in an oxygen atmosphere. In vacuum, the growth rate is consistent with the rates predicted from sintering theory; the experimental evidence suggests that sintering is dr ... [Appl. Phys. Lett. 35, 400 (2008)] published Thu Aug 7, 2008.

400-[A-ring] high aspect-ratio lines produced in poylmethyl methacrylate (PMMA) by ion-beam exposure

L. Karapiperis and C. A. Lee
We report preliminary results on the fabrication of 400- and 2600-A deep lines in polymethyl methacrylate (PMMA) by means of H exposure through a holographically produced fine conformal gold mask. ... [Appl. Phys. Lett. 35, 395 (2008)] published Thu Aug 7, 2008.

Subsurface structures of solids by scanning photoacoustic microscopy

Y. H. Wong, R. L. Thomas, and J. J. Pouch
Definitive experimental evidence is given for the nondestructive detection of subsurface structures of solids by the technique of scanning photoacoustic microscopy (SPAM). In the case of the ceramic materials studied, the thickness of the surface layer probed is dictated by the thermal diffusion len ... [Appl. Phys. Lett. 35, 368 (2008)] published Thu Aug 7, 2008.

Photoacoustic spectroscopy of chrysotile asbestos using a cw HF laser

J.-P. Monchalin, J.-M. Gagne, J.-L. Parpal, and L. Bertrand
We have investigated the feasibility of using a cw HF laser to detect chrysotile asbestos fibers by a photoacoustic technique. We report the photoacoustic spectrum of Canadian chrysotile around its OH absorption band between 3400 and 3800 cm. We have verified that the absorption depends strongly on ... [Appl. Phys. Lett. 35, 360 (2008)] published Thu Aug 7, 2008.

Deleterious effects of an oxidizing drive-in ambient on implanted arsenic emitters in silicon

L. C. Parrillo and B. L. Morris
In -oriented silicon, annealing high-dose (~1 x 10/cm) implanted layers of arsenic in an ambient containing more than a few tenths of 1% oxygen in nitrogen results in dislocation networks that extend well beyond the implanted regions. As the oxygen concentration in the drive-in step is increased, th ... [Appl. Phys. Lett. 35, 345 (2008)] published Thu Aug 7, 2008.

The effect of substrate orientation on the liquid-solid distribution coefficients for Ga[sub x]In[sub 1 - x]As in the temperature range 600--700 [degree]C

T. P. Pearsall, M. Quillec, and M. A. Pollack
We demonstrate that the liquid-solid distribution coefficients depend on the substrate orientation in the growth from the liquid phase of GaInAs. The distribution coefficient of Ga for growth on the (100) face was found to be larger than that for growth on the (111B) face over the entire temperature ... [Appl. Phys. Lett. 35, 342 (2008)] published Thu Aug 7, 2008.

Photoluminescent characterization of GaAs solar cells

G. D. Pettit, J. M. Woodall, and H. J. Hovel
Photoluminescence excitation measurements are shown to accurately determine the spectral response of GaAlAs-GaAs heterojunction solar cells. The technique is applicable to as-grown structures prior to processing into final devices and can also be used to study postgrowth techniques designed to enhan ... [Appl. Phys. Lett. 35, 335 (2008)] published Thu Aug 7, 2008.

Growth of dislocations during laser melting and solidification

J. Narayan and F. W. Young, Jr.
Silicon crystals containing dislocations which terminated in the free surface were melted to depths of about 0.5 [mu]m by rube-laser pulses, and the growth characteristics of dislocations of various types were studied by transmission electron microscopy. It was found that both edge- and screw-type d ... [Appl. Phys. Lett. 35, 330 (2008)] published Thu Aug 7, 2008.

Solar furnace annealing of amorphous Si layers

S. S. Lau, M. von Allmen, I. Golecki, M-A. Nicolet, E. F. Kennedy et al.
We demonstrate that a simple Al solar reflector can be used to induce solid-phase epitaxy of amorphous Si layers obtained either by ion-implantation or ion-deposition techniques. The annealing can be accomplished in air and takes a few seconds for a 1-cm sample area. For ion-implanted samples, the r ... [Appl. Phys. Lett. 35, 327 (2008)] published Thu Aug 7, 2008.

Visualization of the grain-boundary potential barriers of PTC-type BaTiO[sub 3] ceramics by cathodoluminescence in an electron-probe microanalyzer

H. Ihrig and M. Klerk
In PTC-type BaTiO ceramics the grain-boundary potential barriers can easily be made visible by means of cathodoluminescence in an electron-probe microanalyzer without having a voltage applied. The visualization can be explained in the context of our finding that the intensity of the cathodoluminesce ... [Appl. Phys. Lett. 35, 307 (2008)] published Thu Aug 7, 2008.

Energy transfer between 5d electronic states of trivalent rare-earth ions

K. H. Yang and J. A. DeLuca
We have observed 5d-to-5d energy transfer from trivalent Tm to Nd in YF and LuF and Nd to Ce in YF. In a YF : 5 mol% Tm : 1 mol% Nd sample, the probability of energy transfer from Tm to Nd was determined to be 0.94. The 5d-to-5d energy transfer has the possibility of broadening the optical pumping b ... [Appl. Phys. Lett. 35, 301 (2008)] published Thu Aug 7, 2008.

Observation of in situ annealing in hot ion-implantation of nitrogen into Al[sub x]Ga[sub 1 - x]As (x=0.53)

Yunosuke Makita, Hidetoshi Nojiri, Toshio Tsurushima, Hisao Tanoue, and Jun-ichi Shimada
Photoluminescence measurements were carried out for indirect band-gap AlGaAs crystals in which nitrogen ions were implanted at various elevated temperatures. It was found that samples implanted at temperatures higher than 525 degrees C exhibit characteristic emission bands associated with the nitro ... [Appl. Phys. Lett. 35, 293 (2008)] published Thu Aug 7, 2008.

Redistribution of Cr during annealing of [sup 80]Se-implanted GaAs

C. A. Evans, Jr., V. R. Deline, T. W. Sigmon, and A. Lidow
Cr in-depth distributions have been measured in Se-ion-implanted GaAs as a function of postimplant annealing using secondary-ion mass spectrometry (SIMS). Analysis shows that Cr redistributes into regions of residual damage following 800 degrees C annealing. As the damage anneals at higher temperat ... [Appl. Phys. Lett. 35, 291 (2008)] published Thu Aug 7, 2008.

Nucleation-controlled thin-film interactions: Some silicides

R. Anderson, J. Baglin, J. Dempsey, W. Hammer, F. d'Heurle et al.
Silicides formed by the interaction of a metal thin film with a single-crystal silicon substrate usually grow in layers according to diffusion- or reaction-controlled kinetics. The mechanism of the formation of five silicides, IrSi, RhSi, Hf Si, NiSi, and PdSi, share common aspects which set them ca ... [Appl. Phys. Lett. 35, 285 (2008)] published Thu Aug 7, 2008.

Pulsed-electron-beam annealing of polycrystalline-silicon films

T. I. Kamins and A. C. Greenwald
Pulsed-electron-beam annealing of moderately-phosphorus-doped poly-silicon films reduces their resistance below that of thermally annealed films under optimum conditions. In heavily doped films, the electron pulse can cause the effective dopant concentration to exceed that corresponding to solid sol ... [Appl. Phys. Lett. 35, 282 (2008)] published Thu Aug 7, 2008.

Solid-state epitaxial growth of deposited Si films

M. von Allmen, S. S. Lau, J. W. Mayer, and W. F. Tseng
Epitaxial growth by furnace annealing of amorphous Si layers deposited onto Si substrates is demonstrated. Substrate cleaning prior to the evaporation includes only conventional chemical procedures without any attempt to achieve an atomically clean substrate layer interface. The crystalline quality ... [Appl. Phys. Lett. 35, 280 (2008)] published Thu Aug 7, 2008.

Back surface gettering and Cr out-diffusion in VPE GaAs layers

T. J. Magee, J. Peng, J. D. Hong, C. A. Evans, Jr., V. R. Deline et al.
Mechanical back surface damage gettering has been investigated for improving the quality of GaAs substrates and VPE layers on semi-insulating GaAs. It has been shown that the pregettering of substrates reduces the interfacial defect density and alters the level of Cr out-diffusion into the VPE layer ... [Appl. Phys. Lett. 35, 277 (2008)] published Thu Aug 7, 2008.

Carrier-concentration reduction in high-dose phosphorus-implanted silicon caused by wet-oxygen oxidation

K. Yagi, K. Oyu, M. Tamura, and T. Tokuyama
The redistribution of heavily implanted phosphorus atoms (>=1 x 10 ions/cm) in the silicon substrate has been studied for wet-oxygen oxidation in the temperature range 7001000 degrees C. The total carrier concentration of implanted layers is observed to decrease after wet-oxygen oxidation. Electron ... [Appl. Phys. Lett. 35, 275 (2008)] published Thu Aug 7, 2008.

Cellular structure and silicide formation in laser-irradiated metal-silicon systems

G. J. van Gurp, G. E. J. Eggermont, Y. Tamminga, W. T. Stacy, and J. R. M. Gijsbers
Laser irradiation of thin Co, Mo, and Pd films on single-crystalline silicon using Q-switched Nd-YAG laser pulses was shown by He backscattering to result in deep metal penetration into the Si. Evidence of the silicide formation was obtained by x-ray diffraction. Transmission electron microscopy sho ... [Appl. Phys. Lett. 35, 273 (2008)] published Thu Aug 7, 2008.

Spectrally selective surfaces of Ni-pigmented anodic Al[sub 2]O[sub 3]

C. G. Granqvist, A. Andersson, and O. Hunderi
Ni pigmentation of anodic AlO is obtained by electrolytic coloration. Durable coatings with good spectral selectivity (a/e~=8) are produced. Scanning electron microscopy, Auger depth profiling, and atomic absorption analysis lead to the formulation of a detailed structural model, its most essential ... [Appl. Phys. Lett. 35, 268 (2008)] published Thu Aug 7, 2008.

Spray-deposited high-efficiency SnO[sub 2]/n-Si solar cells

Tom Feng, Amal K. Ghosh, and Charles Fishman
SnO/n-Si solar cells (area=1 and 4 cm) having AM1 efficiencies of 12.3% on single-crystal silicon and 10.1% on polycrystalline silicon have been fabricated. The tin oxide is deposited by spraying a SnCl mixture onto heated silicon substrates. Using this low-cost process, large-area (20-cm) single-cr ... [Appl. Phys. Lett. 35, 266 (2008)] published Thu Aug 7, 2008.

Relationships of electrical properties and melting threshold in laser-annealed ion-implanted silicon

K. L. Wang, Y. S. Liu, and C. Burman
This paper describes a study comparing the results of the electrical measurements and the regrowth behavior of ion-implanted silicon annealed with an 80-ns (FWHM) laser pulse at 1.06 [mu]m. Certain correlations were established among the threshold energy density required for melting, the dopant dist ... [Appl. Phys. Lett. 35, 263 (2008)] published Thu Aug 7, 2008.

Microstructure of plasma-deposited a-Si : H films

J. C. Knights and R. A. Lujan
Using transmission and scanning electron microscopy, it is shown that plasma deposition of amorphous silicon hydrogen films from silane or silane/argon mixtures proceeds via nucleation and growth of islands of average lateral dimensions ~100 A. If these islands do not coalesce into a homogeneous fil ... [Appl. Phys. Lett. 35, 244 (2008)] published Thu Aug 7, 2008.

Characterization of neutron-transmutation doping in silicon by the photoluminescence technique

Michio Tajima
The photoluminescence (PL) technique has been applied to the nondestructive characterization of neutron-transmutation doping in silicon crystals for the first time. We demonstrate the simultaneous determination of B and P concentrations both in the starting materials and in the doped crystals by the ... [Appl. Phys. Lett. 35, 242 (2008)] published Thu Aug 7, 2008.

Efficiency enhancement in manganese-doped zinc silicate phosphor with AlPO[sub 4] substitution

I. F. Chang and M. W. Shafer
Large increases in the efficiency of the conventional P1 phosphor (ZnSiO : Mn) have been achieved by substituting various combinations of III and V oxides for SiO, e.g., ZnMnSiAlPO. The photoluminescence efficiency of these phosphors exhibit strong dependence on the AlPO substitution concentration x ... [Appl. Phys. Lett. 35, 229 (2008)] published Thu Aug 7, 2008.

Annealing of phosphorus-ion-implanted silicon using a CO[sub 2] laser

M. Miyao, K. Ohyu, and T. Tokuyama
Annealing behavior of phosphorus implanted in silicon layers under cw CO laser irradiation is investigated. The irradiation time required for full electrical activation is found to depend on the dopant concentration of the substrate. This is because absorption of CO laser light is a function of free ... [Appl. Phys. Lett. 35, 227 (2008)] published Thu Aug 7, 2008.

Ion-beam-induced formation of the PdSi silicide

B. Y. Tsaur, S. S. Lau, and J. W. Mayer
Formation of PdSi has been obtained by implanting energetic Xe ions through a thin Pd (or PdSi) film on a Si substrate. The PdSi phase was found to form near the PdSi-Si interface from Rutherford backscattering measurements. Phase formation was confirmed by glancing-angle x-ray-diffraction analysis. ... [Appl. Phys. Lett. 35, 225 (2008)] published Thu Aug 7, 2008.

Niobium silicide formation induced by Ar-ion bombardment

T. Kanayama, H. Tanoue, and T. Tsurushima
The effect of Ar-ion bombardment on evaporatedNb-on-Si systems has been investigated with He backscattering and x-ray-diffraction measurements. High-dose bombardment with energetic Ar ions was found to induce intermixing between Nb and Si in the form of NbSi. This effect has strong dependence on tem ... [Appl. Phys. Lett. 35, 222 (2008)] published Thu Aug 7, 2008.

A new surface-acoustic-wave cut of quartz with orthogonal temperature-compensated propagation directions

Robert M. O'Connell
A theoretical study of the surface-acoustic-wave (SAW) properties of quartz has produced a new cut which is temperature compensated along two orthogonal directions. This new cut is attractive for use in reflection-grating devices such as the reflective array compressor (RAC), in which orthogonal pro ... [Appl. Phys. Lett. 35, 217 (2008)] published Thu Aug 7, 2008.

Carbon and oxygen role for thermally induced microdefect formation in silicon crystals

Seigo Kishino, Yoshiaki Matsushita, and Masaru Kanamori
Thermally induced microdefect formation phenomena are investigated in connection with oxygen and carbon in silicon crystals by using x-ray diffraction, infrared absorption, and etching/optical microscope observation techniques. In order to investigate the carbon and oxygen role for microdefect forma ... [Appl. Phys. Lett. 35, 213 (2008)] published Thu Aug 7, 2008.

Self-diffusion in intrinsic silicon

Ludomir Kalinowski and Remy Seguin
The silicon self-diffusion in intrinsic silicon was investigated by a new method using stable isotope Si and the ion-analyzer technique. The temperature dependence of the diffusion coefficient was obtained in the range from 885 to 1175 degrees C from which an activation energy 110.6 kcal/mole was o ... [Appl. Phys. Lett. 35, 211 (2008)] published Thu Aug 7, 2008.

The formation of Ga[sub 1 - x]Al[sub x]As layers on the surface of GaAs during continual dissolution into Ga-Al-As solutions

M. B. Small, R. Ghez, R. M. Potemski, and J. M. Woodall
When solid GaAs is placed in an undersaturated solution of Ga, Al, and As, it has been observed that a layer of the solid GaAlAs forms on the surface. In the past the presence of this layer has been attributed to a process of regrowth following sufficient dissolution to saturate the solution. On the ... [Appl. Phys. Lett. 35, 209 (2008)] published Thu Aug 7, 2008.

Amphoteric behavior of Ge implants in GaAs

Y. K. Yeo, J. E. Ehret, F. L. Pedrotti, Y. S. Park, and W. M. Theis
The electrical properties of Ge-implanted GaAs have been studied. Room-temperature implantation was performed at 120 keV with doses ranging from 5 x 10 to 3 x 10/cm. Implanted samples were annealed with pyrolytic SiN encapsulants at temperatures ranging from 700 to 950 degrees C. It was found that ... [Appl. Phys. Lett. 35, 197 (2008)] published Thu Aug 7, 2008.

Low-temperature annealing behavior of GaAs implanted with Be

C. Lawrence Anderson and H. L. Dunlap
Ion implantation of Be into GaAs, followed by annealing at temperatures above 475 degrees C, produces layers with strong p-type conductivity and high hole mobility. Maximum electrical activation of the Be is obtained by 550 degrees C. Be appears to be the only dopant in GaAs which can be electrica ... [Appl. Phys. Lett. 35, 178 (2008)] published Thu Aug 7, 2008.

The characterization of highly-zinc-doped InP crystals

S. Mahajan, W. A. Bonner, A. K. Chin, and D. C. Miller
Highly-zinc-doped InP crystals, grown along the direction by the liquid-encapsulated Czochralski technique, have been characterized by x-ray topography, transmission cathodoluminescence, and transmission electron microscopy. It is observed that high zinc doping improves the perfection of crystals i ... [Appl. Phys. Lett. 35, 165 (2008)] published Thu Aug 7, 2008.

Electron-beam delineation of Pb[sub 1 - x]Sn[sub x]Te films on BaF[sub 2]

W. A. Beck, S. P. Buchner, N. E. Byer, and T. S. Sun
We find that predeposition electron irradiation of the surface of BaF dramatically alters the sticking coefficient for PbSnTe and hence can be used to define MBE-grown films. Auger electron spectroscopy and low-energy-diffraction results indicate that room-temperature e-beam irradiation of the BaF p ... [Appl. Phys. Lett. 35, 163 (2008)] published Thu Aug 7, 2008.

Properties of conducting transparent oxide films produced by ion plating onto room-temperature substrates

R. P. Howson, J. N. Avaratsiotis, M. I. Ridge, and C. A. Bishop
Indium and indium 10% tin oxide films have been produced on room-temperature insulating substrates and have exhibited high conductivities which compare with the best reported for films made at substrate temperatures of 450 degrees C and higher. They were made by the evaporation and sputtering of th ... [Appl. Phys. Lett. 35, 161 (2008)] published Thu Aug 7, 2008.

Sulfur incorporation and thickness variation in vapor-phase-epitaxial GaAs layers for FET's

F. Vidimari
Significant nonuniformities in thickness and carrier concentration were observed in thin GaAs layers grown by VPE on semi-insulating substrates placed parallel to the gas flow in a flat temperature deposition zone. The existence of a boundary layer was taken into account to explain the variation of ... [Appl. Phys. Lett. 35, 158 (2008)] published Thu Aug 7, 2008.

Soft x-ray and vacuum-ultraviolet spectroscopy of ion-beam-heated thin targets

E. J. T. Burns, D. J. Johnson, A. V. Farnsworth, Jr., G. W. Kuswa, G. A. Doschek et al.
XUV spectroscopy utilizing a 1-m grazing incidence spectrograph and photoelectric diodes is used to determine the response of approximately one-proton-range-thick planar targets to an intense beam of hydrogen and carbon ions. Electron temperature, brightness temperature, and total radiated power are ... [Appl. Phys. Lett. 35, 140 (2008)] published Thu Aug 7, 2008.

Metastable [sup 75]As concentrations formed by scanned cw e-beam annealing of [sup 75]As-implanted silicon

J. L. Regolini, T. W. Sigmon, and J. F. Gibbons
The incorporation of As into substitutional lattice sites in silicon in excess of 10 cm is reported. This has been accomplished by both a scanned cw e-beam and a scanned cw laser operating with dwell times in the range of milliseconds. Both electron concentration (using differential van der Pauw) an ... [Appl. Phys. Lett. 35, 114 (2008)] published Thu Aug 7, 2008.

Planar guarded avalanche diodes in InP fabricated by ion implantation

J. P. Donnelly, C. A. Armiento, V. Diadiuk, and S. H. Groves
Planar guarded avalanche diodes in InP have been fabricated using a double-ion-implantation technique. Silicon was selectively implanted into an n-type epitaxial layer to increase the concentration portion of the diode, and beryllium was implanted to form the p-n junction. When appropriately reverse ... [Appl. Phys. Lett. 35, 74 (2008)] published Thu Aug 7, 2008.

Crystallographic orientation of silicon on an amorphous substrate using an artificial surface-relief grating and laser crystallization

M. W. Geis, D. C. Flanders, and Henry I. Smith
Uniform crystallographic orientation of silicon films, 500 nm thick, has been achieved on amorphous fused-silica substrates by laser crystallization of amorphous silicon deposited over surface-relief gratings etched into the substrates. The gratings had a square-wave cross section with a 3.8-[mu]m s ... [Appl. Phys. Lett. 35, 71 (2008)] published Thu Aug 7, 2008.

The use of SnTe as the source of donor impurities in GaAs grown by molecular beam epitaxy

Douglas M. Collins
The use of SnTe as a source of donor impurities in the growth of n-type GaAs by molecular beam epitaxy (MBE) is investigated. Net carrier concentrations n between ~10 and ~10 cm have been obtained with corresponding mobilities of ~38 000 and 2100 cm V sec at 77 degrees K. Sharp changes in donor con ... [Appl. Phys. Lett. 35, 67 (2008)] published Thu Aug 7, 2008.

Tungsten needles produced by decomposition of hexacarbonyltungsten

F. Okuyama, T. Shibata, and N. Yasuda
Tungsten needles grown from hexacarbonyltungsten vapors in a glow-discharge condition are described. The needle growth occurs on a tungsten substrate in a temperature range from nearly room temperature to 1500 degrees K, but needles produced below and above ~1100 degrees K are quite different in m ... [Appl. Phys. Lett. 35, 6 (2008)] published Thu Aug 7, 2008.

Phonon-assisted recombination in a multiple-quantum-well LPE InP-In[sub 1 - x]Ga[sub x]P[sub 1 - z]As[sub z] heterostructure laser

E. A. Rezek, R. Chin, N. Holonyak, Jr., S. W. Kirchoefer, and R. M. Kolbas
By means of computer-controlled liquid-phase epitaxy, multiple-quantum-well InP-InGaPAs (x~0.13, z~0.29) heterostructures of uniform well (L~160 A) and coupling barrier size are grown and are examined in photoluminescence. Laser operation (77 degrees K) of a six-well five-barrier undoped quaternary ... [Appl. Phys. Lett. 35, 45 (2008)] published Thu Aug 7, 2008.

Three-dimensional heat-flow effects in photoacoustic spectroscopy of solids

R. S. Quimby and W. M. Yen
All theories of the photoacoustic effect in solids to date have been one dimensional, ignoring lateral heat transport to the cell walls. By studying the dependence of the photoacoustic signal on the position of focused light on the sample's surface, we have demonstrated experimentally that a three-d ... [Appl. Phys. Lett. 35, 43 (2008)] published Thu Aug 7, 2008.

Surface and bulk order parameters of a nematic liquid crystal

Hitoshi Mada and Shunsuke Kobayashi
The measurements of the anisotropy of the refractive index have been made for heptyl-cyanobiphenyl (7CB) at the surface as well as in the bulk by the interferometric method. Using these data, order parameters S-bar at the surface and S in the bulk were calculated. The results show that S-bar is slig ... [Appl. Phys. Lett. 35, 4 (2008)] published Thu Aug 7, 2008.

Proton radiation effects on Cr-MIS single-crystal Si solar cells

R. Ferraglio and W. A. Anderson
Cr-MIS solar cells on single-crystal Si, with a 2-cm area and approximately 10% efficiency, have been subjected to 1.0- and 1.6-MeV proton radiation at total dosages of up to 3.3 x 10 p/cm. Photovoltaic studies reveal characteristic short-circuit current and open-circuit voltage degradation similar ... [Appl. Phys. Lett. 35, 18 (2008)] published Thu Aug 7, 2008.

Thermochemical coloration and annealing of spinel and magnesium oxide

G. S. White, K. H. Lee, and J. H. Crawford, Jr.
Heating spinel (MgAlO) single crystals in aluminum or magnesium metal vapor at temperatures in excess of 1800 degrees C results in the introduction of an optical absorption band at 5.3 eV. The same band can be produced by heating in a strongly reducing atmosphere with no metal vapor at 2100 degree ... [Appl. Phys. Lett. 35, 1 (2008)] published Thu Aug 7, 2008.

A Scaling Parameter and Function for the Accurate Correlation of Viscosity With Temperature and Pressure Across Eight Orders of Magnitude of Viscosity

Scott Bair and Riccardo Casalini
Quantitative calculations of film thickness and friction in elastohydrodynamic lubrication will require that the low-shear viscosity, [mu], be described with far greater accuracy than it is today. The free volume model has the advantage, over those currently used, of reproducing all of the trends th ... [J. Tribol. 130, 041802 (2008)] published Thu Aug 7, 2008.

EHL Circular Contact Film Thickness Correction Factor for Shear-Thinning Fluids

Punit Kumar and M. M. Khonsari
An extensive set of full elastohydrodynamic lubrication point contact simulations has been used to develop correction factors to account for the effect of shear-thinning lubricant behavior on the central and minimum film thickness in circular contacts under pure rolling condition. The film thickness ... [J. Tribol. 130, 041506 (2008)] published Thu Aug 7, 2008.

Boroxol Rings in Liquid and Vitreous B[sub 2]O[sub 3] from First Principles

Guillaume Ferlat, Thibault Charpentier, Ari Paavo Seitsonen, Akira Takada, Michele Lazzeri et al.
We investigate the structural and vibrational properties of glassy BO using first-principles molecular dynamics simulations. In particular, we determine the boroxol rings fraction f for which there is still no consensus in the literature. Two numerical models containing either a low or a high level ... [Phys. Rev. Lett. 101, 065504 (2008)] published Thu Aug 7, 2008.

Intrinsic Decoherence Mechanisms in the Microcavity Polariton Condensate

A. P. D. Love, D. N. Krizhanovskii, D. M. Whittaker, R. Bouchekioua, D. Sanvitto et al.
The fundamental mechanisms which control the phase coherence of the polariton Bose-Einstein condensate (BEC) are determined. It is shown that the combination of number fluctuations and interactions leads to decoherence with a characteristic Gaussian decay of the first-order correlation function. Thi ... [Phys. Rev. Lett. 101, 067404 (2008)] published Thu Aug 7, 2008.

Partial Crystallinity in Alkyl Side Chain Polymers Dictates Surface Freezing

Shishir Prasad, Zhang Jiang, Sunil K. Sinha, and Ali Dhinojwala
We have studied the structure of a novel crystalline surface monolayer on top of a disordered melt of the same material [poly(n-alkyl acrylate)s] using grazing incidence x-ray diffraction. The grazing incidence x-ray diffraction, surface tension, and bulk latent heat results show that side chains cr ... [Phys. Rev. Lett. 101, 065505 (2008)] published Thu Aug 7, 2008.

Ion-Beam-Induced Collective Rotation of Nanocrystals

Ivo Zizak, Nora Darowski, Siegfried Klaumunzer, Gerhard Schumacher, Jurgen W. Gerlach et al.
Vapor-deposited nanocrystalline titanium layers have been irradiated at room temperature with 350-MeV-Au ions up to 4 x 10 Au/cm. Bombardment-induced texture changes were determined at the BESSY synchrotron light source. During off-normal irradiation, the nanocrystals undergo grain alignment and ro ... [Phys. Rev. Lett. 101, 065503 (2008)] published Thu Aug 7, 2008.

Structure and mechanical properties of diamondlike carbon films produced by hollow-cathode plasma deposition

H. F. Jiang, X. B. Tian, S. Q. Yang, R. K. Y. Fu, and P. K. Chu
Diamondlike carbon (DLC) films are deposited on AISI 304 stainless-steel substrates using hollow-cathode chemical vapor deposition. The effects of the substrate bias on the structural and mechanical properties of the films are studied. X-ray photoelectron spectroscopy reveals the existence of C[Doub ... [J. Vac. Sci. Technol. A 26, 1149 (2008)] published Wed Aug 6, 2008.

On the phase identification of dc magnetron sputtered Pt--Ru alloy thin films

A. P. Warren, R. M. Todi, B. Yao, K. Barmak, K. B. Sundaram et al.
The microstructure and the electronic work function of PtRu alloy thin films spanning the compositional range from pure Pt to pure Ru were investigated. Nominally 50 nm thick films were cosputtered from elemental targets in an ultrahigh vacuum chamber. X-ray reflectivity and Rutherford backscatteri ... [J. Vac. Sci. Technol. A 26, 1208 (2008)] published Wed Aug 6, 2008.

Influence of N[sub 2] gas pressure and negative bias voltage on the microstructure and properties of Cr--Si--N films by a hybrid coating system

Qimin Wang, In-Wook Park, and Kwangho Kim
CrSiN films were deposited using a hybrid coating system combining arc ion plating and magnetron sputtering. The authors investigated the influence of N flux rate and negative bias voltage on the microstructure and properties of CrSiN films, e.g., chemical composition, film morphology, phase structu ... [J. Vac. Sci. Technol. A 26, 1188 (2008)] published Wed Aug 6, 2008.

Identification and quantification of iron silicide phases in thin films

D. R. Miquita, J. C. Gonzalez, M. I. N. da Silva, W. N. Rodrigues, M. V. B. Moreira et al.
Iron silicide samples were grown on Si (111) substrates by solid phase epitaxy and reactive deposition epitaxy. The different iron silicide phases and their correlations with the growth parameters were analyzed by x-ray photoelectron spectroscopy, conversion electron Mossbauer spectroscopy, x-ray di ... [J. Vac. Sci. Technol. A 26, 1138 (2008)] published Wed Aug 6, 2008.

Accurate metrology for laser damage measurements in nonlinear crystals

Anne Hildenbrand, Frank R. Wagner, Hassan Akhouayri, Jean-Yves Natoli, and Mireille Commandre
Accurate laser damage measurements are more difficult to perform in nonlinear optical crystals than in glasses due to several effects proper to these materials or greatly enhanced in these materials. Before discussing these effects, we address the topic of error bar determination for probability mea ... [Opt. Eng. 47, 083603 (2008)] published Wed Aug 6, 2008.

Inverse Lehmann effects can be used as a microscopic pump

Daniel Svensek, Harald Pleiner, and Helmut R. Brand
For cholesteric and chiral smectic liquid crystals a rotation of the helical superstructure can be induced for suitable boundary conditions for external fields such as temperature gradients and electric fields: the Lehmann effect. Here we predict that the inverse effect can lead to a pump for partic ... [Phys. Rev. E 78, 021703 (2008)] published Wed Aug 6, 2008.

Biaxial and uniaxial phases produced by partly repulsive mesogenic models involving D[sub 2h] molecular symmetries

Giovanni De Matteis and Silvano Romano
The present paper considers biaxial nematogenic lattice models, involving particles of D symmetry, whose centers of mass are associated with a three-dimensional simple-cubic lattice. The pair potential is isotropic in orientation space and restricted to nearest neighbors. Let two orthonormal triads ... [Phys. Rev. E 78, 021702 (2008)] published Wed Aug 6, 2008.

Mechanism of ultrafast modulation of the refraction index in photoexcited In[sub x]Ga[sub 1 - x]As/AlAs[sub y]Sb[sub 1 - y] quantum well waveguides

G. W. Cong, R. Akimoto, M. Nagase, T. Mozume, T. Hasama et al.
Ultrafast index change induced by intersubband excitation in InGaAs/AlAsSb quantum well waveguides was evaluated by measuring the phase shift Deltaphi in a wide spectral range of 1.21.7 [mu]m based on a spectral analysis. We obtained a large enhancement in Deltaphi by tuning the probe photon energy ... [Phys. Rev. B 78, 075308 (2008)] published Wed Aug 6, 2008.

Generic guiding principle for the prediction of metal-induced reconstructions of compound semiconductor surfaces

Shenyuan Yang, Lixin Zhang, Hua Chen, Enge Wang, and Zhenyu Zhang
We have performed extensive and systematic ab initio calculations to substantiate a recently proposed generalized electron counting (GEC) rule that governs the rich patterns of compound semiconductor reconstruction induced by metal adsorption. In this rule, the metal adsorbates serve as an electron ... [Phys. Rev. B 78, 075305 (2008)] published Wed Aug 6, 2008.

First-principles theory of infrared absorption spectra at surfaces and interfaces: Application to the Si(100):H[sub 2]O surface

Feliciano Giustino and Alfredo Pasquarello
We calculate the transverse and the longitudinal infrared absorption spectra of the hydrated silicon surface using a first-principles approach. The absorption spectra are computed for two different configurations of water molecules dissociatively chemisorbed on the Si(100)-(2 x 1) surface at full co ... [Phys. Rev. B 78, 075307 (2008)] published Wed Aug 6, 2008.

Electronic structure of multiferroic BiFeO[sub 3] by resonant soft x-ray emission spectroscopy

Tohru Higuchi, Yi-Sheng Liu, Peng Yao, Per-Anders Glans, Jinghua Guo et al.
The electronic structure of multiferroic BiFeO has been studied using soft x-ray emission spectroscopy. The fluorescence spectra exhibit that the valence band is mainly composed of O 2p state hybridized with Fe 3d state. The band gap corresponding to the energy separation between the top of the O 2p ... [Phys. Rev. B 78, 085106 (2008)] published Wed Aug 6, 2008.

Periodized discrete elasticity models for defects in graphene

A. Carpio and L. L. Bonilla
The cores of edge dislocations, edge dislocation dipoles, and edge dislocation loops in planar graphene have been studied by means of periodized discrete elasticity models. To build these models, we have found a way to discretize linear elasticity on a planar hexagonal lattice using combinations of ... [Phys. Rev. B 78, 085406 (2008)] published Wed Aug 6, 2008.

sigma-bonding contribution of a strong pi-acceptor molecule: Surface chemical bond of SO[sub 2] on Ni(100)

T. Tokushima, K. Sodeyama, Y. Harada, Y. Takata, M. Nagasono et al.
We study the electronic structure and chemical bonding of the SO molecule adsorbed on Ni(100) surface using x-ray emission spectroscopy at the O 1s absorption edge. Elemental and symmetry specificities of the method enable us to directly probe surface chemical bonding formed by strong hybridization ... [Phys. Rev. B 78, 085405 (2008)] published Wed Aug 6, 2008.

Lattice dynamics and thermodynamical properties of silicon nitride polymorphs

Akihide Kuwabara, Katsuyuki Matsunaga, and Isao Tanaka
The lattice dynamics of three polymorphs of SiN, alpha, beta, and gamma phases, has been calculated by the real space force constant method combined with first-principles calculations. The thermodynamical properties of the three phases are evaluated from the vibrational density of states. The effect ... [Phys. Rev. B 78, 064104 (2008)] published Wed Aug 6, 2008.

Elongation of gold nanoparticles in silica glass by irradiation with swift heavy ions

Koichi Awazu, Xiaomin Wang, Makoto Fijimaki, Junji Tominaga, Hirohiko Aiba et al.
We examined the mechanism whereby nanoparticles of gold embedded in silica become elongated and oriented parallel to each other on ion irradiation. Elongation occurred for gold particles with radii smaller than 25 nm. The process was simulated by using a thermal spike model. For small-radius nanopar ... [Phys. Rev. B 78, 054102 (2008)] published Wed Aug 6, 2008.

Morphology and flexibility of graphene and few-layer graphene on various substrates

U. Stoberl, U. Wurstbauer, W. Wegscheider, D. Weiss, and J. Eroms
We report on detailed microscopy studies of graphene and few-layer graphene produced by mechanical exfoliation on various semiconducting substrates. We demonstrate the possibility to prepare and analyze graphene on (001)-GaAs, manganese p-doped (001)-GaAs, and InGaAs substrates. The morphology of gr ... [Appl. Phys. Lett. 93, 051906 (2008)] published Wed Aug 6, 2008.

Effect of grain orientation on ductility in a nanocrystalline Ni--Fe alloy

Hongqi LI, Peter K. Liaw, Hahn Choo, and Amit Misra
The influence of columnar grain geometry on mechanical property was studied in an electrodeposited nanocrystalline NiFe alloy. The compressive results show that the strength is independent of grain orientation. However, the plastic strain increased remarkably when the loading axis is parallel to the ... [Appl. Phys. Lett. 93, 051907 (2008)] published Wed Aug 6, 2008.

Suppression of annealing-induced In diffusion in Be-doped GaInAsN/GaAs quantum well

J. Pakarinen, C. S. Peng, V. Polojarvi, A. Tukiainen, V.-M. Korpijarvi et al.
The authors report on an interesting observation regarding thermal annealing of a beryllium-doped GaInAsN/GaAs quantum well (QW) grown by molecular beam epitaxy. A QW doped at 6 x 10 cm exhibited superior thermal properties and about six times larger photoluminescence than an undoped QW of the same ... [Appl. Phys. Lett. 93, 052102 (2008)] published Wed Aug 6, 2008.

Atomic resolution study of the interfacial bonding at Si[sub 3]N[sub 4]/CeO[sub 2 - delta] grain boundaries

W. Walkosz, R. F. Klie, S. Ogut, A. Borisevich, P. F. Becher et al.
Using a combination of atomic-resolution Z-contrast imaging and electron energy-loss spectroscopy (EELS) in the scanning transmission electron microscope, we examine the atomic and electronic structures at the interface between SiN (10[overline 1]0) and CeO intergranular film (IGF). Ce atoms are obs ... [Appl. Phys. Lett. 93, 053104 (2008)] published Wed Aug 6, 2008.

Room temperature epitaxial stabilization of a tetragonal phase in ARuO[sub 3] (A = Ca and Sr) thin films

Arturas Vailionis, Wolter Siemons, and Gertjan Koster
We demonstrate that SrRuO and CaRuO thin films undergo a room temperature structural phase transition driven by the substrate imposed epitaxial biaxial strain. As tensile strain increases, ARuO (A=Ca and Sr) films transform from the orthorhombic phase which is usually observed in bulk SrRuO and CaRu ... [Appl. Phys. Lett. 93, 051909 (2008)] published Wed Aug 6, 2008.

Excitation enhancement of CdSe quantum dots by single metal nanoparticles

Yeechi Chen, Keiko Munechika, Ilan Jen-La Plante, Andrea M. Munro, Sara E. Skrabalak et al.
We study plasmon-enhanced fluorescence from CdSe/CdS/CdZnS/ZnS core/shell quantum dots near a variety of Ag and Au nanoparticles. The photoluminescence excitation (PLE) spectrum of quantum dots closely follows the localized surface plasmon resonance (LSPR) scattering spectrum of the nanoparticles. W ... [Appl. Phys. Lett. 93, 053106 (2008)] published Wed Aug 6, 2008.

Investigation of two-branch boron diffusion from vapor phase in n-type 4H-SiC

A. V. Bolotnikov, P. G. Muzykov, and T. S. Sudarshan
Boron diffusion from gas phase was implemented for p-type doping of 4H-SiC at temperatures in the range of 18002000 degrees C. A two-branch diffusion associated with two different diffusion mechanisms was observed. The activation energy E and prefactor D were calculated for each diffusion branch, ... [Appl. Phys. Lett. 93, 052101 (2008)] published Wed Aug 6, 2008.

Quantitative Analysis of Cavitation Erosion Particle Morphology in Dilute Emulsions

A. Abouel-Kasem, B. Saleh, and S. M. Ahmed
Wear particles produced by vibratory cavitation erosion tests on 1017 carbon steels in water and oil-in-water (o/w) emulsions were analyzed. Scanning electron microscope (SEM) images of wear particles were acquired, forming a database for further analysis. The particle morphology features were first ... [J. Tribol. 130, 041603 (2008)] published Wed Aug 6, 2008.

Polarized light interferometer for laser fusion studies

R. Benattar, C. Popovics, and R. Sigel
A polarized light interferometer, suitable for the high-speed photography of microscopic objects in laser fusion experiments, is described. Based on a Wollaston prism as beam splitter, its main advantages are its relative simplicity, the absence of alignment and stability problems, and the extended ... [Rev. Sci. Instrum. 50, 1583 (2008)] published Wed Aug 6, 2008.

Thermal expansion of solids at high temperatures by the gamma attenuation technique

William D. Drotning
A new technique is described for the measurement of the thermal expansion of isotropic solid materials at high temperatures. The method utilizes gamma attenuation to measure thermal expansion with a noncontacting probe. The experimental apparatus and analytical method are described, and results are ... [Rev. Sci. Instrum. 50, 1567 (2008)] published Wed Aug 6, 2008.

Computer-controlled system for measuring two-dimensional acoustic velocity fields

D. B. Ilic, G. S. Kino, and A. R. Selfridge
An automatic system is described for measuring two-dimensional acoustic velocity fields in solid samples. The measurement is performed by a computer-controlled, mechanically scanned transducer in a liquid bath, and is based on measuring the phase delay of the acoustic wave by a two-pulse echo method ... [Rev. Sci. Instrum. 50, 1527 (2008)] published Wed Aug 6, 2008.

Direct continuous measurements of thermal expansion coefficients of liquids and solids using flow microcalorimetry

Jean-Luc Fortier, Marc-Andre Simard, Patrick Picker, and Carmel Jolicoeur
A differential heat capacity flow microcalorimeter is used to monitor in a continuous mode the thermal expansion of a sample during a programmed temperature scan. The sample may consist of liquids, suspensions, or bulk solids in a confining liquid and the typical temperature scanning rate is of the ... [Rev. Sci. Instrum. 50, 1474 (2008)] published Wed Aug 6, 2008.

Design and characteristics of a cell for photoacoustic spectroscopy of condensed matter

D. Ducharme, A. Tessier, and R. M. Leblanc
We describe a photoacoustic cell which is simple to use, easy to construct, and which gives a great sensitivity, expressed as a signal-to-noise ratio of 3000. Calibration of the cell indicates that it can be used with confidence as a general purpose photoacoustic cell. ... [Rev. Sci. Instrum. 50, 1461 (2008)] published Wed Aug 6, 2008.

Method for the determination of the specific heat of metals at low temperatures under high pressures

Andreas Eichler and Wolfgang Gey
Efforts are made to determine the absolute specific heat of metals as a function of pressure with an accuracy, which, for the first time, will permit a direct evaluation of the pressure variation of the electronic and phonon parameters gamma and theta, respectively. This is achieved by employing the ... [Rev. Sci. Instrum. 50, 1445 (2008)] published Wed Aug 6, 2008.

Multiwavelength optical pyrometer for shock compression experiments

G. A. Lyzenga and Thomas J. Ahrens
A system for measurement of the spectral radiance of materials shocked to high pressures (~100 GPa) by impact using a light gas gun is described. Thermal radiation from the sample is sampled at six wavelength bands in the visible spectrum, and each signal is separately detected by solid-state photod ... [Rev. Sci. Instrum. 50, 1421 (2008)] published Wed Aug 6, 2008.

New Kerr cell for low-temperature measurements

J. Crossley, B. K. Morgan, and M. Rujimethabhas
A Kerr cell has been constructed which can be used to study the Kerr effect in liquids from room temperature down to 77 K. At low temperatures, the cell windows are free of moisture. The cell has been tested and measurements on liquid carbon disulfide, between 170 and 300 K, are discussed. ... [Rev. Sci. Instrum. 50, 1400 (2008)] published Wed Aug 6, 2008.

Optoelectronic modulation of a laser interferometer in the infrared for accurate electron density variation measurements

A. Lesage, J. Richou, P. Charil, M. Combier, and J. L. Lebrun
An improved method for high-electron-density (10 cm) measurement in a shock-generated plasma is described. A laser interferometer operated at 3.39 [mu]m is regularly modulated (1 MHz) by a LiNbO electro-optical crystal. Thus electron-density variations of 8 x 10 cm [mu]s and fluctuation of 8 x 10 cm ... [Rev. Sci. Instrum. 50, 1306 (2008)] published Wed Aug 6, 2008.

High-accuracy differential measurement of ultrasonic velocity in liquids

John G. Elias and Don Eden
An improved technique for measuring very accurately the difference in sound velocity between two liquids is described. The technique, which can be used over a frequency range from 1 to 100 MHz, uses a differential cell that is completely submerged in a thermostatically controlled fluid and a phase-s ... [Rev. Sci. Instrum. 50, 1299 (2008)] published Wed Aug 6, 2008.

Production of reproducible Rayleigh--Taylor instabilities

R. Popil and F. L. Curzon
A device is described that excites individual modes of the standing wave spectrum for surface waves on water in a water tank of rectangular cross section. By synchronizing the downward acceleration of the tank with the standing wave on the water, RayleighTaylor instabilities with reproducible charac ... [Rev. Sci. Instrum. 50, 1291 (2008)] published Wed Aug 6, 2008.

Ultrafast Pockels cells for the infrared

Edward J. McLellan and Joseph F. Figueira
The design and performance of a 2.25-cm-aperture Pockels cell system for 10-[mu]m radiation is described. Pulses as short as 90 ps can be reliably generated with this device. ... [Rev. Sci. Instrum. 50, 1213 (2008)] published Wed Aug 6, 2008.

System for continuous monitoring of point defect concentrations during irradiations and anneals

J. J. Jackson and E. A. Ryan
An integrated system, cryostat, electronics, and computer used for detailed resistivity measurements during low-temperature irradiations and anneals of metals is described. The thermal response time and rate of heat removal from the specimens are optimized. The system has excellent stability for ext ... [Rev. Sci. Instrum. 50, 1193 (2008)] published Wed Aug 6, 2008.

Transient conductivity measurements with subnanosecond time resolution

G. Beck
The parameters governing the response time of a system to follow transient changes of conductivity caused by short pulses of radiation are discussed, and designs for coaxial conductivity cells with parallel-plate electrodes to obtain subnanosecond time resolution are described. The performance of th ... [Rev. Sci. Instrum. 50, 1147 (2008)] published Wed Aug 6, 2008.

A new instrument for measuring surface pressure

M. Stenberg and H. Lofgren
A new instrument for surface pressure measurements using a floating-foil technique has been constructed. The instrument makes use of a probe in the form of a thin foil suspended at the gas/liquid or liquid/liquid interface tension. The present instrument has a dynamic range of 0.170 mN/m and a sensi ... [Rev. Sci. Instrum. 50, 1098 (2008)] published Wed Aug 6, 2008.

A capacitance-based micropositioning system for x-ray rocking curve measurements

G. L. Miller, R. A. Boie, P. L. Cowan, J. A. Golovchenko, R. W. Kerr et al.
Certain types of x-ray experiments require very precise angular positioning of crystals in the vicinity of the Bragg reflection condition. A system applicable to some measurement of this type is described which achieves a long-term angular stability of ~10 radians, coupled with a linear angular read ... [Rev. Sci. Instrum. 50, 1062 (2008)] published Wed Aug 6, 2008.

Automatic measurement of temperature in a nuclear reactor

A. Youssefkhani
A circuit has been developed to display the temperatures measured using platinum resistance thermometers. The thermometer number and the temperature are displayed sequentially together with the highest temperature and the number of the corresponding thermometer. ... [Rev. Sci. Instrum. 50, 979 (2008)] published Wed Aug 6, 2008.

Microscopy in electron diffraction apparatus

S. Yamaguchi
A simple method was devised for observing electron micrographs as well as diffraction figures from a given object. A dielectric emulsion composed of paraffin and barium titanate acted here as an electrostatic lens when charged up with the incident electrons. Electron diffraction figures could immedi ... [Rev. Sci. Instrum. 50, 919 (2008)] published Wed Aug 6, 2008.

Apparatus for in situ creep testing during irradiation with high-energy neutrons from a planar neutron source

W. L. Barmore, A. W. Ruotola, and R. R. Vandervoort
An apparatus is described for investigating the in situ creep behavior of materials during irradiation with neutrons having a spectrum similar to that of a fusion power reactor. Techniques are discussed for remote, high-vacuum creep testing during irradiation with high-energy neutrons from a planar ... [Rev. Sci. Instrum. 50, 844 (2008)] published Wed Aug 6, 2008.

Versatile electron spectrometer for surface studies

G. E. Thomas and W. H. Weinberg
An electron spectrometer is described which is designed to measure a variety of electron spectra of solid surfaces in ultrahigh vacuum. The instrument is capable of the high-energy resolution (1015 meV) required for vibrational inelastic electron scattering from atoms and molecules on surfaces. It h ... [Rev. Sci. Instrum. 50, 497 (2008)] published Wed Aug 6, 2008.

Simple apparatus for measuring the dynamic shear modulus of cylindrical specimens

H. M. Simpson and J. Pearson
An apparatus is decribed which has been used to determine the shear modulus of cylindrical specimens vibrating in the torsional mode. The specimens are maintained in self-excited vibration by an eddy-current driver, an eddy-current pickup, and a feed back circuit consisting of a phase-locked-loop an ... [Rev. Sci. Instrum. 50, 418 (2008)] published Wed Aug 6, 2008.

Measurement of gradient index profiles by Babinet fringe analysis

T. P. Pandya and A. K. Saxena
A theory for determining one-dimensional ray deflections with the help of distorted Babinet fringes has been developed. An approach for investigating two-dimensional ray deflections has been presented. Applications of the techniques for the study of gradient index glass have been described. ... [Rev. Sci. Instrum. 50, 369 (2008)] published Wed Aug 6, 2008.

Stress apparatus for magneto-transport and far-infrared magneto-optical experiments

F. Kuchar, K. Veigl, and E. J. Fantner
A stress apparatus is reported which allows us to apply forces up to 300 N to solids perpendicular to the field in a superconducting magnet. This configuration is necessary to study stress dependences of transverse magneto-transport effects and magneto-optical properties in Faraday geometry. The use ... [Rev. Sci. Instrum. 50, 245 (2008)] published Wed Aug 6, 2008.

Quartz optoacoustic apparatus for highly corrosive gases

E. E. Marinero and M. Stuke
In this paper we report on a new optoacoustic apparatus designed for the study of highly corrosive gases. The sound transducer is a thin quartz membrane sintered to one end of the solid quartz acoustic chamber. Measurements were performed on iodine chloride. Construction details, performance charact ... [Rev. Sci. Instrum. 50, 241 (2008)] published Wed Aug 6, 2008.

Analysis of a photographic--vidicon camera method of LEED intensity measurements

T. N. Tommet, G. B. Olszewski, P. A. Chadwick, and S. L. Bernasek
Low-energy electron diffraction (LEED) has great need for a quick and efficient means of making intensity measurements (e.g., in studying reactive surfaces which quickly degrade, and in handling the enormous amounts of data needed for data averaging). The photographicvidicon camera method fills this ... [Rev. Sci. Instrum. 50, 147 (2008)] published Wed Aug 6, 2008.

Raman study of self-assembled InAs/InP quantum wire stacks with varying spacer thickness

T. Angelova, A. Cros, A. Cantarero, D. Fuster, Y. Gonzalez et al.
Self-assembled InAs/InP (001) quantum wire stacks have been investigated by means of Raman scattering. The characteristics of the observed vibrational modes show clear evidence of confinement and atomic intermixing between As and P atoms from the wire and the spacer. The change in the intermixing wi ... [J. Appl. Phys. 104, 033523 (2008)] published Wed Aug 6, 2008.

Nanocrystalline Ba[sub 0.97]Ca[sub 0.03]SO[sub 4]:Eu for ion beams dosimetry

S. P. Lochab, D. Kanjilal, Numan Salah, Sami S. Habib, Jyoti Lochab et al.
Nanoparticles of BaCaSO:Eu have been irradiated by 48 MeV Li, 75 MeV C, and 90 MeV O ion beams with a fluence range of 1 x 101 x 10 ion/cm. The thermoluminescence (TL) glow curves along with the response curves of this nanophosphor have been investigated and compared with those of the corresponding ... [J. Appl. Phys. 104, 033520 (2008)] published Wed Aug 6, 2008.

Investigations of dopants introduction in hafnia: Electronic properties, diffusion, and their role on the gate leakage current

Valerie Cuny and Nicolas Richard
To understand the role of dopants in the electronic properties of monoclinic hafnium dioxide, we have performed first-principles simulations using density functional theory. The structure, ionization energies, electron affinities, formation energies, and activation energies for fluorine and nitrogen ... [J. Appl. Phys. 104, 033709 (2008)] published Wed Aug 6, 2008.

Optical properties of thermally annealed hafnium oxide and their correlation with structural change

Jun-Woo Park, Do-Kyu Lee, D. Lim, Hosun Lee, and Suk-Ho Choi
We studied the optical properties of hafnium oxide as its structure changed. The shoulderlike feature that appears in crystalline HfO near the energy trough of the optical absorption edge after thermal anneal was found to have a direct correlation with the crystallization of the film. A luminescence ... [J. Appl. Phys. 104, 033521 (2008)] published Wed Aug 6, 2008.

Electrically controlled Kerr effect in magnetophotonic crystals based on nematic liquid crystals

H. X. Da, P. Xu, J. C. Wu, and Z. Y. Li
An electrically controllable Kerr effect in magnetophotonic crystals consisting of magnetic materials and nematic liquid crystals is presented by considering the properties of nematic liquid crystals. Numerical results show that the Kerr effect is changed remarkably by adjusting the permittivity of ... [J. Appl. Phys. 104, 033911 (2008)] published Wed Aug 6, 2008.

Direct measurement of hot-spot temperature in flip-chip solder joints under current stressing using infrared microscopy

Hsiang-Yao Hsiao, S. W. Liang, Min-Feng Ku, Chih Chen, and Da-Jeng Yao
Several simulation studies reported that a hot spot exists in flip-chip solder bumps under accelerated electromigration. Yet, there are no experimental data to verify it. In this paper, the temperature distribution during electromigration in flip-chip SnAg3.5 solder bumps is directly inspected using ... [J. Appl. Phys. 104, 033708 (2008)] published Wed Aug 6, 2008.

Acoustic modes of finite length homogeneous and layered cylindrical shells: Single and multiwall carbon nanotubes

Guangyan Li, G. A. Lamberton, Jr., and J. R. Gladden
We present a numerical study of the normal modes of vibration of both homogeneous and heterogeneous finite length cylindrical shells of arbitrary wall thickness with applications toward single and multiwall carbon nanotubes in the continuum limit. The method is checked by comparison of computed and ... [J. Appl. Phys. 104, 033524 (2008)] published Wed Aug 6, 2008.

Effects of rapid thermal annealing on optical properties of p-doped and undoped InAs/InGaAs dots-in-a-well structures

Q. Cao, S. F. Yoon, C. Y. Liu, and C. Z. Tong
Postgrowth rapid thermal annealing was used to investigate the intermixing and structural changes in p-doped and undoped InAs/InGaAs dots-in-a-well (DWELL) structures grown by molecular beam epitaxy. Interdiffusion of In and Ga atoms caused by thermal annealing was proven from photoluminescence (PL) ... [J. Appl. Phys. 104, 033522 (2008)] published Wed Aug 6, 2008.

Quantum Differences between Heavy and Light Water

A. K. Soper and C. J. Benmore
The structures of heavy and light water at ambient conditions are investigated with the combined techniques of x-ray diffraction, neutron diffraction, and computer simulation. It is found that heavy water is a more structured liquid than light water. We find the OH bond length in HO is ~3% longer th ... [Phys. Rev. Lett. 101, 065502 (2008)] published Wed Aug 6, 2008.

Non-Markovian Decoherence of Localized Nanotube Excitons by Acoustic Phonons

Christophe Galland, Alexander Hogele, Hakan E. Tureci, and Atac Imamoglu
We demonstrate that electron-phonon interaction in quantum dots embedded in one-dimensional systems leads to pronounced, non-Markovian decoherence of optical transitions. The experiments that we present focus on the line shape of photoluminescence from low-temperature axially localized carbon nanotu ... [Phys. Rev. Lett. 101, 067402 (2008)] published Wed Aug 6, 2008.

Photoinduced Change in the Charge Order Pattern in the Quarter-Filled Organic Conductor (EDO-TTF)[sub 2]PF[sub 6] with a Strong Electron-Phonon Interaction

Ken Onda, Sho Ogihara, Kenji Yonemitsu, Nobuya Maeshima, Tadahiko Ishikawa et al.
The quasistable state in the photoinduced phase transition for the quasi-one-dimensional quarter-filled organic conductor (EDO-TTF)PF has been examined by ultrafast reflective measurements and time-dependent model calculations incorporating both electron-electron and electron-phonon interactions. Th ... [Phys. Rev. Lett. 101, 067403 (2008)] published Wed Aug 6, 2008.

ac Vortex-Dependent Torsional Oscillation Response and Onset Temperature T[sub 0] in Solid [sup 4]He

Andrey Penzev, Yoshinori Yasuta, and Minoru Kubota
Detailed studies of ac velocity V and T dependence of torsional oscillator responses of solid He are reported. A characteristic onset temperature T~0.5 K is found, below which a significant V-dependent change occurs in the energy dissipation for the samples at ~32 bar and for one at 49 bar. A V de ... [Phys. Rev. Lett. 101, 065301 (2008)] published Wed Aug 6, 2008.

Resonant Raman scattering from polyacetylene and poly(p-phenylene vinylene) chains included into hydrogenated amorphous carbon

M. Rybachuk, A. Hu, and J. M. Bell
The resonant Raman scattering in N-IRUV range from amorphous hydrogenated carbon (a-C:H) reveals inclusions of trans-polyacetylene [trans-(CH)] chains with approximate length of up to 120 C[Double Bond]C units and inclusions of poly(p-phenylene vinylene) (PPV) polymer chains. The PPV is evidenced by ... [Appl. Phys. Lett. 93, 051904 (2008)] published Tue Aug 5, 2008.

Sharp growth of nickel plasticity under impact load near Curie point

Michel Molotskii
We proposed an explanation of the recent observations by Zaretsky [Appl. Phys. Lett. 92, 011913 (2008)] who discovered sharp increase in nickel plasticity under impact loading near Curie temperature T. Growth of plasticity is explained by reduction in dynamical deceleration of dislocations controlle ... [Appl. Phys. Lett. 93, 051905 (2008)] published Tue Aug 5, 2008.

Local structure of indium oxynitride from x-ray absorption spectroscopy

J. T-Thienprasert, J. Nukeaw, A. Sungthong, S. Porntheeraphat, S. Singkarat et al.
Synchrotron x-ray absorption near edge structures (XANES) measurements of In L edge is used in conjunction with first principles calculations to characterize rf magnetron sputtered indium oxynitride at different O contents. Good agreement between the measured and the independently calculated spectra ... [Appl. Phys. Lett. 93, 051903 (2008)] published Tue Aug 5, 2008.

Interband physics in an ultracold Fermi gas in an optical lattice

J.-P. Martikainen, E. Lundh, and T. Paananen
We study a gas of strongly polarized cold fermions in an optical lattice when the excited p bands are populated. We derive the relevant Hamiltonian and discuss the expected phase diagram for both repulsive and attractive interactions. In the parameter regime covered here, checkerboard antiferromagne ... [Phys. Rev. A 78, 023607 (2008)] published Tue Aug 5, 2008.

Bayesian approach to the calculation of lateral interactions: NO/Rh(111)

A. P. J. Jansen and C. Popa
We show how Bayesian statistics and density-functional theory can be combined to compute reliable values for the interactions in a cluster expansion for adsorbates on a surface. The method is an alternative to the leave-one-out cross-validation method. We show that it easily selects which interactio ... [Phys. Rev. B 78, 085404 (2008)] published Tue Aug 5, 2008.

Chemical structures of the Cu(In,Ga)Se[sub 2]/Mo and Cu(In,Ga)(S,Se)[sub 2]/Mo interfaces

M. Bar, L. Weinhardt, C. Heske, S. Nishiwaki, and W. N. Shafarman
Using a suitable lift-off technique, we have investigated the chemical properties of the interface between Mo and chalcopyrite compound semiconductors by x-ray photoelectron spectroscopy and x-ray excited Auger-electron spectroscopy. By a systematic comparison of interfaces between S-free [Cu(In,Ga) ... [Phys. Rev. B 78, 075404 (2008)] published Tue Aug 5, 2008.

Structural, electronic, and surface properties of anatase TiO[sub 2] nanocrystals from first principles

Amilcare Iacomino, Giovanni Cantele, Domenico Ninno, Ivan Marri, and Stefano Ossicini
The structural and electronic properties of anatase TiO nanocrystals (NCs) are investigated through first-principles calculations. The dependence of the structural properties (e.g., NC volume variations) on the surface chemistry is discussed by considering two different surface coverages (dissociate ... [Phys. Rev. B 78, 075405 (2008)] published Tue Aug 5, 2008.

Intermediate-range order in the silicate network glasses NaFe[sub x]Al[sub 1 - x]Si[sub 2]O[sub 6] (x = 0,0.5,0.8,1): A neutron diffraction and empirical potential structure refinement modeling investigation

C. Weigel, L. Cormier, G. Calas, L. Galoisy, and D. T. Bowron
The local structural environment, and the spatial distribution of iron and aluminum ions in sodosilicate glasses with composition NaFeAlSiO (x=1, 0.8, 0.5, and 0) were studied by high-resolution neutron diffraction combined with structural modeling using the empirical potential structure refinement ... [Phys. Rev. B 78, 064202 (2008)] published Tue Aug 5, 2008.

Voltage-assisted asperity formation in styrene butadiene at room temperature: Cross-linking at the nanoscale

M. Rackaitis, D. Kashyn, E. Rowicka, P. B. Paramonov, R. R. Mallik et al.
Nanoscale surface modification is reported for styrene butadiene rubber using an electrically biased conducting atomic force microscope tip. Under appropriate bias conditions, the local electric field magnitude is of the order of 1010 V m, which is sufficiently large to initiate cross-linking in th ... [Phys. Rev. B 78, 064201 (2008)] published Tue Aug 5, 2008.

Theoretical description of pressure- and temperature-induced structural phase transition mechanisms of nitrogen

Hannelore Katzke and Pierre Toledano
A theoretical description is proposed for the pressure- and temperature-induced structural transitions of nitrogen. Three regions of the phase diagram are distinguished corresponding to different types of transition mechanisms and parent structures. Combined ordering and displacive reconstructive tr ... [Phys. Rev. B 78, 064103 (2008)] published Tue Aug 5, 2008.

Classical Wigner theory of gas surface scattering

Eli Pollak, Santanu Sengupta, and Salvador Miret-Artes
The scattering of atoms from surfaces is studied within the classical Wigner formalism. A new analytical expression is derived for the angular distribution and its surface temperature dependence. The expression is valid in the limit of weak coupling between the vertical motion with respect to the su ... [J. Chem. Phys. 129, 054107 (2008)] published Tue Aug 5, 2008.

Phase transition induced by a shock wave in hard-sphere and hard-disk systems

Nanrong Zhao, Masaru Sugiyama, and Tommaso Ruggeri
Dynamic phase transition induced by a shock wave in hard-sphere and hard-disk systems is studied on the basis of the system of Euler equations with caloric and thermal equations of state. First, RankineHugoniot conditions are analyzed. The quantitative classification of Hugoniot types in terms of th ... [J. Chem. Phys. 129, 054506 (2008)] published Tue Aug 5, 2008.

Phase transition induced by a shock wave in hard-sphere and hard-disk systems

Nanrong Zhao, Masaru Sugiyama, and Tommaso Ruggeri
Dynamic phase transition induced by a shock wave in hard-sphere and hard-disk systems is studied on the basis of the system of Euler equations with caloric and thermal equations of state. First, RankineHugoniot conditions are analyzed. The quantitative classification of Hugoniot types in terms of th ... [J. Chem. Phys. 129, 054506 (2008)] published Tue Aug 5, 2008.