Precise in situ thickness analysis of epitaxial graphene layers on SiC(0001) using low-energy electron diffraction and angle resolved ultraviolet photoelectron spectroscopy
C. Riedl, A. A. Zakharov, and U. Starke
We demonstrate an easy and practical method for the thickness analysis of epitaxial graphene on SiC(0001) that can be applied continuously during the preparation procedure. Fingerprints in the spot intensity spectra in low energy electron diffraction (LEED) allow for the exact determination of the n ... [Appl. Phys. Lett. 93, 033106 (2008)] published Wed Jul 23, 2008.
Radiotracer diffusion of cobalt, iron, and chromium in dislocation-free germanium
L. Lerner and N. A. Stolwijk
Diffusion of the transition metals Co, Fe, and Cr into single-crystal germanium is found to be fast processes at temperatures relevant to the fabrication of semiconductor devices. These results were obtained from experiments in which electronic-grade Ge samples were provided with a radioactive surfa ... [Appl. Phys. Lett. 93, 032107 (2008)] published Wed Jul 23, 2008.
Mechanical twinning and omega transition by {112} shear in a metastable beta titanium alloy
H. Xing and J. Sun
{112} mechanical twinning and stress-induced omega transition were observed by high-resolution transmission electron microscope in a metastable beta titanium alloy with chemical composition of Ti-23Nb-0.7Ta-2Zr-1.2O at. % after deformation. The orientation relationships between the omega phase and ... [Appl. Phys. Lett. 93, 031908 (2008)] published Wed Jul 23, 2008.
Sum-frequency phonon spectroscopy on alpha-quartz
Wei-Tao Liu and Y. R. Shen
We demonstrate here, using alpha-quartz as an example, that IR-visible sum-frequency (SF) spectroscopy can be employed to probe zone-center optical phonons of crystals without inversion symmetry. Because only modes both IR and Raman active are allowed in the SF process, the observed phonon spectrum ... [Phys. Rev. B 78, 024302 (2008)] published Wed Jul 23, 2008.
Crystal structure, phase transition, and magnetic ordering in perovskitelike Pb[sub 2 - x]Ba[sub x]Fe[sub 2]O[sub 5] solid solutions
Ivan V. Nikolaev, Hans D'Hondt, Artem M. Abakumov, Joke Hadermann, Anatoly M. Balagurov et al.
The crystal and magnetic structures of the x[approximate]1 member of the PbBaFeO solid solution series have been studied using x-ray and neutron powder diffraction, electron diffraction, high-resolution electron microscopy, and Mossbauer spectroscopy. PbBaFeO has two polymorphic forms with the ortho ... [Phys. Rev. B 78, 024426 (2008)] published Wed Jul 23, 2008.
Energy transfer in Er-doped SiO[sub 2] sensitized with Si nanocrystals
I. Izeddin, D. Timmerman, T. Gregorkiewicz, A. S. Moskalenko, A. A. Prokofiev et al.
We present a high-resolution photoluminescence study of Er-doped SiO sensitized with Si nanocrystals (Si NCs). Emission bands originating from recombination of excitons confined in Si NCs, internal transitions within the 4f-electron core of Er ions, and a band centered at lambda[approximate]1200 nm ... [Phys. Rev. B 78, 035327 (2008)] published Wed Jul 23, 2008.
Gas separation by kinked single-walled carbon nanotubes: Molecular dynamics simulations
ZhongQiang Zhang, HongWu Zhang, YongGang Zheng, Lei Wang, and JinBao Wang
In this paper, a kink model for gas separation is presented. Transport of pure nitrogen, oxygen, and their mixture in single-walled carbon nanotubes (SWCNTs) with a kink formed by bending is studied using molecular dynamics simulations. The results show that a nanotube with a specified kink results ... [Phys. Rev. B 78, 035439 (2008)] published Wed Jul 23, 2008.
Lattice Green function for extended defect calculations: Computation and error estimation with long-range forces
D. R. Trinkle
Computing the atomic geometry of lattice defectse.g., point defects, dislocations, crack tips, surfaces, or boundariesrequires an accurate coupling of the local deformations to the long-range elastic field. Periodic or fixed boundary conditions used by classical potentials or density-functional theo ... [Phys. Rev. B 78, 014110 (2008)] published Wed Jul 23, 2008.
Molecular dynamics simulations of the Debye-Waller effect in shocked copper
William J. Murphy, Andrew Higginbotham, Justin S. Wark, and Nigel Park
We present an analysis of the directionally dependent x-ray structure factors (and, hence, intensities) predicted by nonequilibrium molecular dynamics simulations of statically compressed and shocked single crystals of copper, and comment on the feasibility of using experimentally measured intensiti ... [Phys. Rev. B 78, 014109 (2008)] published Wed Jul 23, 2008.
Giant asymmetry of soft x-ray magnetic scattering between opposite circular polarizations near the Brewster angle
Dae-Eun Jeong and Sang-Koog Kim
Giant asymmetry in soft x-ray resonant reflectivities of left- and right-handed circular polarization modes of an incident p-polarized beam from 3d transition-metal films was studied using newly developed theoretical and numerical calculations of soft x-ray resonant magnetic scattering based on the ... [Phys. Rev. B 78, 012412 (2008)] published Wed Jul 23, 2008.
Transmission-line analysis of epsilon-near-zero--filled narrow channels
Andrea Alu, Mario G. Silveirinha, and Nader Engheta
Following our recent interest in metamaterial-based devices supporting resonant tunneling, energy squeezing, and supercoupling through narrow waveguide channels and bends, here we analyze the fundamental physical mechanisms behind this phenomenon using a transmission-line model. These theoretical fi ... [Phys. Rev. E 78, 016604 (2008)] published Wed Jul 23, 2008.
Transient damage spreading and anomalous scaling in mortar crack surfaces
Stephane Morel, Daniel Bonamy, Laurent Ponson, and Elisabeth Bouchaud
The scaling properties of a post-mortem mortar crack surface are investigated. The root mean square of the height fluctuations is found to obey anomalous scaling properties, but with three exponents, two of them characterizing the local roughness (zeta~=0.79 and zeta~=0.41) and the third one driving ... [Phys. Rev. E 78, 016112 (2008)] published Wed Jul 23, 2008.
Osmotic pressure and polymer size in semidilute polymer solutions under good-solvent conditions
Andrea Pelissetto
We consider the lattice DombJoyce model at a value of the coupling for which scaling corrections approximately vanish and determine the universal scaling functions associated with the osmotic pressure and the polymer size for semidilute polymer solutions (c/c<=10, where c is the concentration of the ... [J. Chem. Phys. 129, 044901 (2008)] published Wed Jul 23, 2008.
A direct approach to study radiative emission from triplet excitations in molecular semiconductors and conjugated polymers
Jai Singh, H. Baessler, and S. Kugler
Using the recently discovered time-dependent spin-orbit-photon interaction operator and first order perturbation theory, the rate of spontaneous emission from triplet excitations is derived within the two-level approximation for organic molecular solids and conjugated polymers. The calculated rates ... [J. Chem. Phys. 129, 041103 (2008)] published Wed Jul 23, 2008.
Diffusion in linear porous media with periodic entropy barriers: A tube formed by contacting spheres
Marco-Vinicio Vazquez, Alexander M. Berezhkovskii, and Leonardo Dagdug
The problem of transport in quasi-one-dimensional periodic structures has been studied recently by several groups [D. Reguera et al., Phys. Rev. Lett.96, 130603 (2006); P. S. Burada et al., Phys. Rev. E75, 051111 (2007); B. Q. Ai and L. G. Liu, ibid.74, 051114 (2006); B. Q. Ai et al., ibid.75, 06112 ... [J. Chem. Phys. 129, 046101 (2008)] published Wed Jul 23, 2008.
Formation and diffusion of oxygen-vacancy pairs on TiO[sub 2](110)-(1 x 1)
Xuefeng Cui, Bing Wang, Zhuo Wang, Tian Huang, Yan Zhao et al.
We present the measurements for the diffusion of bridging oxygen vacancy (OV) crossover Ti rows via OV pairs (OVPs). Using a high-resolution scanning tunneling microscope (STM), we show that the OVs can be moved along the bridging oxygen rows driven by the STM tip at voltages higher than 3.0 V on Ti ... [J. Chem. Phys. 129, 044703 (2008)] published Wed Jul 23, 2008.
Comment on ``Molybdenum at High Pressure and Temperature: Melting from Another Solid Phase''
C. Cazorla, D. Alfe, and M. J. Gillan
A Comment on the Letter by A. B. Belonoshko et al., Phys. Rev. Lett. 100, 135701 (2008). The authors of the Letter offer a Reply. ... [Phys. Rev. Lett. 101, 049601 (2008)] published Wed Jul 23, 2008.
Liquid-Liquid Interfacial Tension of Electrolyte Solutions
Markus Bier, Jos Zwanikken, and Rene van Roij
It is theoretically shown that the excess liquid-liquid interfacial tension between two electrolyte solutions as a function of the ionic strength I behaves asymptotically as [script O](-sqrt(I)) for small I and as [script O](I) for large I. The former regime is dominated by the electrostatic potenti ... [Phys. Rev. Lett. 101, 046104 (2008)] published Wed Jul 23, 2008.
Cheng et al. Reply:
M. T. Cheng, P. Bianucci, A. Muller, H. J. Zhou, Q. Q. Wang et al.
A Reply to the Comment by Yujun Zheng. ... [Phys. Rev. Lett. 101, 049702 (2008)] published Wed Jul 23, 2008.
Plasmon-Induced Transparency in Metamaterials
Shuang Zhang, Dentcho A. Genov, Yuan Wang, Ming Liu, and Xiang Zhang
A plasmonic molecule consisting of a radiative element coupled with a subradiant (dark) element is theoretically investigated. The plasmonic molecule shows electromagnetic response that closely resembles the electromagnetically induced transparency in an atomic system. Because of its subwavelength d ... [Phys. Rev. Lett. 101, 047401 (2008)] published Wed Jul 23, 2008.
Comment on ``Coherent Control of a V-Type Three-Level System in a Single Quantum Dot''
Yujun Zheng
A Comment on the Letter by Q. Q. Wang et al., Phys. Rev. Lett. 95, 187404 (2005). The authors of the Letter offer a Reply. ... [Phys. Rev. Lett. 101, 049701 (2008)] published Wed Jul 23, 2008.
Mikhaylushkin et al. Reply:
A. S. Mikhaylushkin, S. I. Simak, L. Burakovsky, S. P. Chen, B. Johansson et al.
A Reply to the Comment by C. Cazorla, D. Alfe, and M. J. Gillan. ... [Phys. Rev. Lett. 101, 049602 (2008)] published Wed Jul 23, 2008.
Crackling Dynamics in Material Failure as the Signature of a Self-Organized Dynamic Phase Transition
D. Bonamy, S. Santucci, and L. Ponson
We derive here a linear elastic stochastic description for slow crack growth in heterogeneous materials. This approach succeeds in reproducing quantitatively the intermittent crackling dynamics observed recently during the slow propagation of a crack along a weak heterogeneous plane of a transparent ... [Phys. Rev. Lett. 101, 045501 (2008)] published Wed Jul 23, 2008.
Viscosity of concentrated sucrose and trehalose aqueous solutions including the supercooled regime
M. Paula Longinotti and Horacio R. Corti
The viscosity of aqueous solutions of sucrose and trehalose is analyzed over a wide range of concentrations and temperatures covering the normal liquid and supercooled liquid regions, close to the glass transition temperature. These sugar solutions are fragile systems whose viscosity exhibits temper ... [J. Phys. Chem. Ref. Data 37, 1503 (2008)] published Wed Jul 23, 2008.
Modification of the classical nucleation theory based on molecular simulation data for surface tension, critical nucleus size, and nucleation rate
Martin Horsch, Jadran Vrabec, and Hans Hasse
Nucleation in supersaturated vapor is investigated with two series of molecular-dynamics simulations in the canonical ensemble. The applied methods are (a) analysis of critical nuclei at moderate supersaturations by simulating equilibria of single droplets with surrounding vapors in small systems; ( ... [Phys. Rev. E 78, 011603 (2008)] published Tue Jul 22, 2008.
Path-independent integrals to identify localized plastic events in two dimensions
Mehdi Talamali, Viljo Petaja, Damien Vandembroucq, and Stephane Roux
We use a power expansion representation of plane-elasticity complex potentials due to Kolossov and Muskhelishvili to compute the elastic fields induced by a localized plastic deformation event. Far from its center, the dominant contributions correspond to first-order singularities of quadrupolar and ... [Phys. Rev. E 78, 016109 (2008)] published Tue Jul 22, 2008.
Optical imaging of the effect of in-plane fields on cholesteric liquid crystals
S. A. Jewell and J. R. Sambles
The effects of in-plane electric fields on the director structure of cholesteric liquid crystals has been imaged in three dimensions using fluorescence confocal polarizing microscopy. The results show that a liquid crystal lying outside the electrode gap can be significantly affected by stray fields ... [Phys. Rev. E 78, 012701 (2008)] published Tue Jul 22, 2008.
Spontaneous formation of Mn nanocluster arrays on a Si(111)-7 x 7 surface observed with STM
Jun-Zhong Wang, Jin-Feng Jia, Zu-Hong Xiong, and Qi-Kun Xue
An extreme low-deposition rate has been used to fabricate highly ordered Mn nanocluster arrays on A Si(111)-7 x 7 surface. Scanning tunneling microscopy (STM) studies reveal that the Mn nanoclusters prefer to occupy the faulted half-unit cells of the Si(1110)-7 x 7 with preference fraction ~95%. Hig ... [Phys. Rev. B 78, 045424 (2008)] published Tue Jul 22, 2008.
Lattice expansion in nonoxidized FePt nanoparticles: X-ray absorption measurements
C. Antoniak, A. Trunova, M. Spasova, M. Farle, H. Wende et al.
Wet-chemically synthesized FePt nanoparticles were structurally characterized not only in the as-prepared state but also after the removal of organic ligands and reduction in Fe oxides by a soft in situ hydrogen plasma treatment. By the analyses of the extended x-ray absorption fine structures at th ... [Phys. Rev. B 78, 041406 (2008)] published Tue Jul 22, 2008.
Response to ``Comment on `Quasiferromagnetism in semiconductors''' [Appl. Phys. Lett. [bold 93], 036101 (2008)]
T. Dubroca, R. E. Hummel, and A. Angerhofer
... [Appl. Phys. Lett. 93, 036102 (2008)] published Tue Jul 22, 2008.
Reduced heat flow in light water (H[sub 2]O) due to heavy water (D[sub 2]O)
William R. Gorman and James D. Brownridge
The flow of heat, from top to bottom, in a column of light water can be decreased by over 1000% with the addition of heavy water. A column of light water cools from 25 to 0 degrees C in 11 h, however, with the addition of heavy water it takes more than 100 h. There is a concentration dependenc ... [Appl. Phys. Lett. 93, 034101 (2008)] published Tue Jul 22, 2008.
Laser induced popcornlike conformational transition of nanodiamond as a nanoknife
Chia-Ching Chang, Pei-Hsin Chen, Hsueh-Liang Chu, Tzu-Cheng Lee, Ching-Chung Chou et al.
Nanodiamond (ND) is surrounded by layers of graphite on its surface. This unique structure feature creates unusual fluorescence spectra, which can be used as an indicator to monitor its surface modification. Meanwhile, the impurity, nitroso (C[Single Bond]N[Double Bond]O) inside the ND can be photol ... [Appl. Phys. Lett. 93, 033905 (2008)] published Tue Jul 22, 2008.
Comment on ``Quasiferromagnetism in semiconductors'' [Appl. Phys. Lett. [bold 88], 182504 (2006)]
Yun-Chung Chi, Yuan-Yao Wei, Jiunn-Hsing Chao, and Yung Liou
... [Appl. Phys. Lett. 93, 036101 (2008)] published Tue Jul 22, 2008.
Composite fermionization of one-dimensional Bose-Bose mixtures
Sascha Zollner, Hans-Dieter Meyer, and Peter Schmelcher
We study the ground states of one-dimensional Bose-Bose mixtures under harmonic confinement. As we vary the interspecies coupling strength up to the limit of infinite repulsion, we observe a generalized, composite-fermionization crossover. The initially coexisting phases demix as a whole for weak in ... [Phys. Rev. A 78, 013629 (2008)] published Tue Jul 22, 2008.
Anomalous enhancement of quasiparticle current near a potential barrier in a Bose-Einstein condensate
Shunji Tsuchiya and Yoji Ohashi
We investigate tunneling properties of Bogoliubov phonons in a Bose-Einstein condensate. We find the anomalous enhancement of the quasiparticle current J carried by Bogoliubov phonons near a potential barrier, due to the supply of the excess current from the condensate. This effect leads to the incr ... [Phys. Rev. A 78, 013628 (2008)] published Tue Jul 22, 2008.
First-order spatial coherence of excitons in planar nanostructures: A k-filtering effect
L. Mouchliadis and A. L. Ivanov
We propose and analyze a k-filtering effect which gives rise to the drastic difference between the actual spatial coherence length of quasi-two-dimensional excitons or microcavity polaritons in planar nanostructures and that inferred from far-field optical measurements. The effect originates from co ... [Phys. Rev. B 78, 033306 (2008)] published Tue Jul 22, 2008.
Phase transformation of iron under shock compression: Effects of voids and shear stress
Xinlin Cui, Wenjun Zhu, Hongliang He, Xiaoliang Deng, and Yingjun Li
Unlike the perfect single crystals, most engineering materials contain a large number of defects that would affect their properties critically. By introducing a nanovoid into the single-crystal iron, the shock-induced phase transformation of body-centered cubic alpha phase to hexagonal close-packed ... [Phys. Rev. B 78, 024115 (2008)] published Tue Jul 22, 2008.
Structural origin of the x-ray diffuse scattering in (CH[sub 3])[sub 4]NCdCl[sub 3] and related compounds
Marek Pasciak, Marek Wolcyrz, and Adam Pietraszko
The local structure of (CH)NCdCl (TMCC) has been determined by a configurational-bias reverse Monte Carlo method applied to x-ray diffuse scattering data. The following two phases have been analyzed and refined: phase I at 293 K, P6/m space group, a=9.139(1)A, and c=6.723(1)A; and phase I at 410 K, ... [Phys. Rev. B 78, 024114 (2008)] published Tue Jul 22, 2008.
Critical fluctuations and random-anisotropy glass transition in nematic elastomers
G. Feio, J. L. Figueirinhas, A. R. Tajbakhsh, and E. M. Terentjev
We carry out a detailed deuterium nuclear magnetic resonance (NMR) study of local nematic ordering in polydomain nematic elastomers. This system has a close analogy to the random-anisotropy spin glass. We find that, in spite of the quadrupolar nematic symmetry in three dimensions requiring a first-o ... [Phys. Rev. B 78, 020201 (2008)] published Tue Jul 22, 2008.
Heat Treatment and Interface Effects on the Mechanical Behavior of SiC-Particle Reinforced Aluminium Matrix Composites
D. P. Myriounis, S. T. Hasan, and T. E. Matikas
The interface plays a vital role in composites. Strengthening behavior of SiC-particle reinforced aluminium matrix composites relies on load transfer behavior across the interface, whereas toughness is influenced by crack deflection at the boundary between matrix and reinforcement and ductility is a ... [J. ASTM Int. 5, 101624 (2008)] published Tue Jul 22, 2008.
Atomic-scale study of low-temperature equilibria in iron-rich Al-C-Fe
Remy Besson, Alexandre Legris, Damien Connetable, and Philippe Maugis
The capability of the thermodynamic approach based on the independent point defect approximation to describe low-temperature phase equilibria is investigated and applied to the Al-C-Fe system. The method gives a reasonable description of the multicomponent and multisublattice Fe-rich corner and evid ... [Phys. Rev. B 78, 014204 (2008)] published Tue Jul 22, 2008.
Full-Color and Thermally Stable KSrPO[sub 4]:Ln (Ln = Eu, Tb, Sm) Phosphors for White-Light-Emitting Diodes
C. C. Lin, R. S. Liu, Y. S. Tang, and S. F. Hu
The novel phosphors of KSrPO doped with Eu, Tb, and Sm were synthesized by solid-state reaction, and their luminescence properties were investigated. The phosphors show pure three-basal-color (red-green-blue) luminescence in the CIE1931 chromaticity diagram, and it was observed that the concentratio ... [J. Electrochem. Soc. 155, J248 (2008)] published Tue Jul 22, 2008.
Electrothermal Bonding of Carbon Nanotubes to Glass
Sriharsha V. Aradhya, Suresh V. Garimella, and Timothy S. Fisher
Applications that exploit the exceptional properties of carbon nanotubes (CNTs) at practical length scales almost invariably involve the fundamental issues of nanotube-to-surface contacts; indeed, interface properties often dominate mechanical, electrical, and thermal performance in devices and mate ... [J. Electrochem. Soc. 155, K161 (2008)] published Tue Jul 22, 2008.
Characterization of Threading Dislocations in Thin Germanium Layers by Defect Etching: Toward Chromium and HF-Free Solution
L. Souriau, T. Atanasova, V. Terzieva, A. Moussa, M. Caymax et al.
Defect etching is a fast and simple technique for the revelation of defects in single-crystalline materials. We propose here three different chemistries that allow accurate monitoring of the density of threading dislocations in germanium. This work especially focuses on solutions that have low etch ... [J. Electrochem. Soc. 155, H677 (2008)] published Tue Jul 22, 2008.
The coupled electric field effects on localized surface plasmon resonance in nanoparticle arrays
Shaoyun Yin, Qiling Deng, Xiangang Luo, Chunlei Du, and Yudong Zhang
When a metal nanoparticle exhibits its unique dipole plasmon resonance, optical properties can be treated by considering a point dipole. Here we established a strong correlation between the surface-plasmon-induced coupled electric field in nanoparticle arrays and the extinction peak shifts. The mode ... [J. Appl. Phys. 104, 024308 (2008)] published Tue Jul 22, 2008.
Intermediate phases in rhombohedral Pb(Mg[sub 1/3]Nb[sub 2/3])[sub 1 - x]Ti[sub x]O[sub 3] crystal
C.-S. Tu, H.-T. Chuang, S.-C. Lee, R. R. Chien, V. H. Schmidt et al.
Phase transformations of (111)-cut Pb(MgNb)TiO (x=0.30) single crystals before and after an electric (E)field poling have been investigated by means of dielectric permittivity, hysteresis loop, polarization current, and in situ x-ray diffraction as a function of temperature. An R-T-C transition sequ ... [J. Appl. Phys. 104, 024110 (2008)] published Tue Jul 22, 2008.
Distribution and segregation of arsenic at the[bold ]SiO[sub 2]/Si interface
C. Steen, A. Martinez-Limia, P. Pichler, H. Ryssel, S. Paul et al.
The segregation and pile-up of arsenic atoms at the Si/SiO interface in steady state was investigated in detail by a combination of gracing incidence x-ray fluorescence spectroscopy (GI-XRF) measurements, electrical measurements, etching on the nanometer scale, and measurements of the step heights b ... [J. Appl. Phys. 104, 023518 (2008)] published Tue Jul 22, 2008.
Finite system size effects in the interfacial dynamics of binary liquid films
Amol K. Thakre, J. T. Padding, W. K. den Otter, and W. J. Briels
We study the relaxation dynamics of capillary waves in the interface between two confined liquid layers by means of molecular dynamics simulations. We measure the autocorrelations of the interfacial Fourier modes and find that the finite thickness of the liquid layers leads to a marked increase of t ... [J. Chem. Phys. 129, 044701 (2008)] published Tue Jul 22, 2008.
On the comparison of transmission electron microscopy and channeled Rutherford backscattering techniques to evaluate the multilayer subsurface damage structures
D. K. Sadana, M. Strathman, J. Washburn, and G. R. Booker
Cross-sectional transmission electron microscopy (TEM) and MeV He channeling methods have been used to examine different damage structures present under the color bands visible at the surface of a high-dose-rate P-implanted (111) Si wafer implanted to a dose of 7.5 x 10 ions/cm. TEM and channeling r ... [Appl. Phys. Lett. 37, 234 (2008)] published Tue Jul 22, 2008.
Photoluminescence study of perturbed growth of InP on quaternary layers in InGaAsP-InP double heterostructures
E. V. K. Rao, M. Quillec, J.-L. Benchimol, and H. Thibierge
Photoluminescence (PL) spectra of InGaAsP-InP laser double heterostructures show evidence for perturbed growth in the top InP confinement layers. The PL spectra of these layers are found to be a bnormally wide and exhibit two emission features hitherto unobserved in single InP epilayers. This pertur ... [Appl. Phys. Lett. 37, 228 (2008)] published Tue Jul 22, 2008.
Plastic deformation and fracture resulting from stresses caused by differential thermal contraction in GaP/Si heterostructures
R. K. Tsui and M. Gershenzon
Cleavage cracks form in thick (>~5 [mu]m) GaP layers deposited epitaxially on Si during the cooldown after growth. The distribution of stresses caused by differential thermal contraction in such heterostructures has been analyzed, and suggests that stress relief through plastic deformation explains ... [Appl. Phys. Lett. 37, 218 (2008)] published Tue Jul 22, 2008.
Effect of Si dissolution and recrystallization upon ohmic Al/p-Si contacts
D. Dascalu, Gh. Brezeanu, and P. A. Dan
The electrical behavior of a sintered Al/p-Si ohmic contact is evaluated by means of a new computer fitting technique, the diameter perturbation method. Both the specific contact resistance and the semiconductor resistivity are accurately determined. The effect of sintering temperature and duration ... [Appl. Phys. Lett. 37, 215 (2008)] published Tue Jul 22, 2008.
Shallow silicide-to-silicon contacts: The case of amorphous-Pd[sub 80]Si[sub 20]--to--silicon
S. Kritzinger and K. N. Tu
It is known that fabrication of shallow silicide-to-silicon contacts is possible by diluting the silicide-forming metal with some other metal which does not participate in silicide formation at the chosen annealing temperature. We report preliminary experiments undertaken to develop contacts which a ... [Appl. Phys. Lett. 37, 205 (2008)] published Tue Jul 22, 2008.
Double heteroepitaxy in the Si (111)/CoSi[sub 2]/Si structure
Shyuichi Saitoh, Hiroshi Ishiwara, and Seijiro Furukawa
Epitaxial growth of CoSi films on Si substrates and the growth of Si films on the Si(111)/CoSi structure are investigated. Solid phase epitaxy is used to grow both CoSi and Si films. Molecular beam epitaxy is also used to grow the top Si films in the double heteroepitaxy. It has been found that two ... [Appl. Phys. Lett. 37, 203 (2008)] published Tue Jul 22, 2008.
Evidence for partial solid-state regrowth during pulsed-laser annealing
J. M. Gibson and R. Tsu
Nonsecond pulsed-laser annealing of semiconductors is widely believed to be a simple thermal melting and recrystallization effect. We have examined subthreshold-irradiated arsenic-implanted silicon wafers in cross section by conventional transmission and scanning transmission electron microscopy. Bo ... [Appl. Phys. Lett. 37, 197 (2008)] published Tue Jul 22, 2008.
Diffusion and structural relaxation in compositionally modulated amorphous metal films
M. P. Rosenblum, F. Spaepen, and D. Turnbull
The interdiffusivity in compositionally modulated (lambda[approximate]25 A) amorphous (PdSi)/(FeB) and (PdAuSi)/Fe films has been measured by monitoring the satellite of the (000) x-ray scattering peak during isothermal anneals in the range 210250 degrees C. Diffusivities as low as 10 cm s have bee ... [Appl. Phys. Lett. 37, 184 (2008)] published Tue Jul 22, 2008.
Lattice defects in As-implanted and cw Nd:YAG laser-annealed silicon
K. Ishida, H. Okabayashi, and M. Yoshida
Lattice defects in As-implanted and cw Nd:YAG laser-annealed silicon have been studied. Observed defects are small point defect clusters at lower laser power which develop into dislocation loops at higher laser power. Further increase of laser power results in annihilation of the dislocation loop, b ... [Appl. Phys. Lett. 37, 175 (2008)] published Tue Jul 22, 2008.
Interface grading in InGaAsP liquid phase epitaxial heterostructures
L. W. Cook, M. Feng, M. M. Tashima, R. J. Blattner, and G. E. Stillman
Auger depth profiles on InGaAs-InP and InGaAs-InGaAsP heterojunctions grown by liquid phase epitaxial (LPE) techniques have been measured. For InGaAs-InP and InGaAsP-InGaAs-InGaAsP heterostructures where the lattice mismatch Deltaa/a between the grown layers is less than 0.03%, the chemical transiti ... [Appl. Phys. Lett. 37, 173 (2008)] published Tue Jul 22, 2008.
Supersaturated solid solutions after solid phase epitaxial growth in Bi-implanted silicon
S. U. Campisano, E. Rimini, P. Baeri, and G. Foti
The lattice location of Bi-implanted (100) Si after thermal treatment at 550 degrees C has been studed by a channeling effect technique. Supersaturated substitutional solid solutions are formed with a Bi concentration in excess of 500 times the maximum solid solubility. After growth good crystallin ... [Appl. Phys. Lett. 37, 170 (2008)] published Tue Jul 22, 2008.
Deep deuterium traps in Y-implanted Fe
S. M. Myers, S. T. Picraux, and R. E. Stoltz
Ion-implanted Y in Fe is shown to trap deuterium with an enthalpy of ~=1.3 eV. This binding is the strongest yet reported for a hydrogen isotope in an Fe-based alloy. The trapping is attributed to a Y-vacancy complex, with the coupling being augmented by a Y-hydrogen chemical interaction. ... [Appl. Phys. Lett. 37, 168 (2008)] published Tue Jul 22, 2008.
Ambient effects on the diffusion of Cr and Si in thin Pt films
Chin-An Chang and W.-K. Chu
We have studied the ambient effects on the low-temperature diffusion of Cr and Si in thin Pt films. The surface-potential model proposed earlier predicts that, contrary to the case in gold, oxygen should suppress the diffusion of Cr and Si in Pt. We have observed a reduced out-diffusion of Cr and a ... [Appl. Phys. Lett. 37, 161 (2008)] published Tue Jul 22, 2008.
Oxygen striation and thermally induced microdefects in Czochralski-grown silicon crystals
A. Ohsawa, K. Honda, S. Ohkawa, and K. Shinohara
Oxygen striations in Czochralski-grown silicon crystals have been directly observed by applying the scanning IR absorption technique to longitudinal sections. The oxygen striations were found to correlate clearly with thermally-induced-microdefect distributions. The results show that oxygen plays a ... [Appl. Phys. Lett. 37, 157 (2008)] published Tue Jul 22, 2008.
New distillation apparatus
Bruno Lunelli
A novel design for a vaporizer which induces a vapor flow pattern producing a centrifugal field is described. This design completely avoids contamination of the vapor, and hence of the distillate, by splashes of liquid, which is a severe problem in small scale, reduced pressure distillations. Other ... [Rev. Sci. Instrum. 51, 832 (2008)] published Tue Jul 22, 2008.
Method for simultaneous measuring diffusion coefficients and refractive index dependence on concentration at different wavelengths
Ernest Karawacki
An experimental procedure is described making it possible to determine from one diffusion experiment both the diffusion coefficient D and the dependence of the refractive index on concentrations [partial-derivative][mu]/[partial-derivative]c for many wavelengths of light. The results from the measur ... [Rev. Sci. Instrum. 51, 789 (2008)] published Tue Jul 22, 2008.
An apparatus for the measurement of the rates of emanation of radon from rock specimens and powders
R. H. McCorkell and M. P. Brameld
Specimens are placed in sealed chambers to which scintillation cells are attached and radon concentrations, R, are measured in the air of the chambers at intervals thereafter by inserting the cells into scintillation counters. The Rn emanation rate is calculated from the rate at which R increases, o ... [Rev. Sci. Instrum. 51, 459 (2008)] published Tue Jul 22, 2008.
Experimental facility to produce and measure compression and shear waves in impacted solids
Y. M. Gupta, D. D. Keough, D. F. Walter, K. C. Dao, D. Henley et al.
An impact facility has been designed and constructed to produce and measure large amplitude one-dimensional compression and shear waves in solids. Design considerations and experimental details to produce the necessary impact configuration and to measure the particle velocity profiles resulting from ... [Rev. Sci. Instrum. 51, 183 (2008)] published Tue Jul 22, 2008.
Direct measurement of internal friction with continuous variation of frequency
S. C. Lakkad and Y. P. Karnik
A method for the measurement of the internal friction in solids by measuring the instantaneous values of applied sinusoidal stress, the resulting strain and the phase difference between them is presented in this paper. The experimental setup utilizes the instruments normally used in the vibration an ... [Rev. Sci. Instrum. 51, 1124 (2008)] published Tue Jul 22, 2008.
A scanning laser probe for the direct observation of acoustic wave phenomena at liquid--solid interfaces
Douglas A. Davids
A novel system has been developed for the direct measurement of acoustic displacement at a liquidsolid interface which is useful in the observation of leaky wave and related beam-shift phenomena. Theory predicts that under certain conditions the acoustic field configuration is sensitive to material ... [Rev. Sci. Instrum. 51, 1059 (2008)] published Tue Jul 22, 2008.
Multichannel digitizer for routine monitoring of ion emission from laser-driven implosions
A. Raven, P. T. Rumsby, and J. Watson
The design and construction of a multichannel Faraday cup detector and digitizer system for routine monitoring of ion emission characteristics from laser driven implosions are discussed. Experimental results are presented to demonstrate the operation of the device. ... [Rev. Sci. Instrum. 51, 351 (2008)] published Tue Jul 22, 2008.
Thickness measurement of a thin oxide layer by secondary electron emission
K. Okamoto
A method for measuring the thickness of a very thin oxide layer by secondary electron emission is described. The secondary electron signals are measured for an oxide-covered silicon surface and a reference surface by using the line mode of scanning electron microscope. Then, their ratio correlates w ... [Rev. Sci. Instrum. 51, 302 (2008)] published Tue Jul 22, 2008.
Vibrational modes of metal nanoshells and bimetallic core-shell nanoparticles
Arman S. Kirakosyan and Tigran V. Shahbazyan
We theoretically study the spectrum of radial vibrational modes in composite metal nanostructures such as bimetallic core-shell particles and metal nanoshells with dielectric core in an environment. We calculate frequencies and damping rates of fundamental (breathing) modes for these nanostructures ... [J. Chem. Phys. 129, 034708 (2008)] published Mon Jul 21, 2008.
Atomistic structure dependence of the collective excitation in metal nanoparticles
Christian F. A. Negre and Cristian G. Sanchez
From a simple time-dependent tight-binding model, we calculate the absorption spectra of a series of metallic nanoparticles of varying size and shape. Spheres and spheroids of varying aspect ratios as well as a number of polyhedral particle shapes are studied. The frequency of the maximum absorption ... [J. Chem. Phys. 129, 034710 (2008)] published Mon Jul 21, 2008.
Topological effect in ring polymers investigated with Monte Carlo simulation
Jiro Suzuki, Atsushi Takano, and Yushu Matsushita
We studied equilibrium conformations of ring polymers in the melt over the wide range of segment number up to 1000 by the Monte Carlo simulations and the bond fluctuation model, and estimated Flory's scaling exponent nu. The radial distribution function of segments for the ring polymers in the melt ... [J. Chem. Phys. 129, 034903 (2008)] published Mon Jul 21, 2008.
Polycrystalline Si nanoparticles and their strong aging enhancement of blue photoluminescence
Shikuan Yang, Weiping Cai, Haibo Zeng, and Zhigang Li
Nearly spherical polycrystalline Si nanoparticles with 20 nm diameter were fabricated based on laser ablation of silicon wafer immersed in sodium dodecyl sulfate aqueous solution. Such Si nanoparticles consist of disordered areas and ultrafine grains of 3 nm in mean size and exhibit significant phot ... [J. Appl. Phys. 104, 023516 (2008)] published Mon Jul 21, 2008.
Room temperature ferromagnetism of Sn[sub 1 - x]Co[sub x]O[sub 2 - delta] films fabricated by sol-gel method
Yalu Zuo, Shihui Ge, YuXuan Zhao, Xueyun Zhou, Yuhua Xiao et al.
Co-doped SnO thin films were fabricated by sol-gel method. All the samples have pure rutile polycrystalline structure and exhibit room temperature ferromagnetism (RTFM). SnCoO films spin coated on Si (111) substrate have larger magnetic moment than those on Si (amorphous) substrate. X-ray photoelect ... [J. Appl. Phys. 104, 023905 (2008)] published Mon Jul 21, 2008.
Laser induced effects on ZnO targets upon ablation at 266 and 308 nm wavelengths
Maria Jadraque, Concepcion Domingo, and Margarita Martin
The development of structural changes in ZnO targets, upon laser irradiation at the wavelengths of 266 and 308 nm, is studied by Raman spectroscopy. At the wavelength of 308 nm, oxygen vacancies are found to develop monotonically with increasing laser intensity. At 266 nm, a structural change in ... [J. Appl. Phys. 104, 024306 (2008)] published Mon Jul 21, 2008.
Spatially resolved residual stress assessments of GaN film on sapphire substrate by cathodoluminescence piezospectroscopy
Giuseppe Pezzotti, Alessandro Alan Porporati, Andrea Leto, and Wenliang Zhu
Two cathodoluminescence piezospectroscopic (CL/PS) approaches for measuring the residual stress distribution in thin films are critically examined and compared using an intrinsic GaN film sample (2.5 [mu]m in thickness) grown on a (0001)-oriented sapphire substrate. The first approach invokes an an ... [J. Appl. Phys. 104, 023514 (2008)] published Mon Jul 21, 2008.
Structural conditions that leads to photoluminescence emission in SrTiO[sub 3]: An experimental and theoretical approach
V. M. Longo, A. T. de Figueiredo, S. de Lazaro, M. F. Gurgel, M. G. S. Costa et al.
Complex cluster [TiOV] and [SrOV] (where V=V, V, V) vacancies were identified in disordered SrTiO powders prepared by the polymeric precursor method, based on experimental measurements by x-ray absorption near edge structure spectroscopy. The paramagnetic complex states of [TiOV] and [SrOV] with unp ... [J. Appl. Phys. 104, 023515 (2008)] published Mon Jul 21, 2008.
Yb-induced (2 x 3) and (2 x 4) reconstructions on Si(100) studied by first-principles calculations and high-resolution core-level photoelectron spectroscopy
M. Kuzmin, M. P. J. Punkkinen, P. Laukkanen, R. E. Perala, M. Ahola-Tuomi et al.
We report here a combined theoretical and experimental study of Yb/Si(100)(2 x 3) and (2 x 4) reconstructions by means of first-principles calculations and high-resolution core-level photoelectron spectroscopy. Energetically stable atomic structures are presented for these reconstructions. Yb atoms ... [Phys. Rev. B 78, 045318 (2008)] published Mon Jul 21, 2008.
Analysis of the photoconduction in CaF[sub 2]:Eu[sup 2+] crystals using the microwave resonant cavity technique
H. Loudyi, Y. Guyot, S. A. Kazanskii, J.-C. Gacon, B. Moine et al.
The microwave resonant cavity technique (MRCT) was used to measure the room-temperature photoconductivity spectrum of a CaF:Eu single crystal between 275 and 450 nm, with the aim of positioning the Eu levels relatively to the bottom of the host conduction band. A photoconductivity signal was detecte ... [Phys. Rev. B 78, 045111 (2008)] published Mon Jul 21, 2008.
Thermal transport in a semiconductor heterostructure measured by time-resolved x-ray diffraction
Y. M. Sheu, S. H. Lee, J. K. Wahlstrand, D. A. Walko, E. C. Landahl et al.
We report studies of thermal transport across the interface of a semiconductor heterostructure using x-ray diffraction to measure the time-dependent lattice expansion after ultrafast laser excitation. Femtosecond laser pulses are used to rapidly and locally heat the substrate at the buried interface ... [Phys. Rev. B 78, 045317 (2008)] published Mon Jul 21, 2008.
Strain relief through stair-rod dislocations in ultrathin epitaxial metal films: Defect geometry and energetics
A. Klein, W. Meyer, A. Schmidt, B. Gumler, S. Muller et al.
Epitaxial Ni films deposited on Ir(100) were investigated by tunneling microscopy (STM), quantitative low-energy electron diffraction (LEED), and density-functional theory (DFT). For film thicknesses beyond 3 monolayers the large tensile strain ([approximate]9%) is relieved by the formation of stair ... [Phys. Rev. B 78, 045422 (2008)] published Mon Jul 21, 2008.
Isolated rigid rod behavior of functionalized single-wall carbon nanotubes in solution determined via small-angle neutron scattering
A. Urbina, C. Miguel, J. L. Delgado, F. Langa, C. Diaz-Paniagua et al.
The measurement of small-angle neutron scattering on functionalized single-wall carbon nanotubes in solution is reported. Without the use of surfactants, isolated rigid rod behavior of functionalized single-wall carbon nanotubes has been observed. The onset of pinning between the nanotubes at differ ... [Phys. Rev. B 78, 045420 (2008)] published Mon Jul 21, 2008.
High-temperature annealing and surface photovoltage shifts on Si(111)7 x 7
H. M. Zhang, Kazuyuki Sakamoto, G. V. Hansson, and R. I. G. Uhrberg
The relation between annealing temperature and surface photovoltage (SPV) shifts on the Si(111)7 x 7 surface of lightly n-doped substrates has been studied by core-level and valence-band photoelectron spectroscopies at 100 K. The SPV shift was found to depend strongly on the annealing temperature an ... [Phys. Rev. B 78, 035318 (2008)] published Mon Jul 21, 2008.
Homoepitaxial growth of Bi(111)
G. Jnawali, H. Hattab, C. A. Bobisch, A. Bernhart, E. Zubkov et al.
Homoepitaxial growth of Bi(111) at temperatures between 80300 K has been studied using spot profile analyzing low-energy electron diffraction (SPA-LEED) and scanning tunneling microscopy (STM). From the intensity oscillations of the (00)-spot with Bi coverage and the STM topography of two-dimensiona ... [Phys. Rev. B 78, 035321 (2008)] published Mon Jul 21, 2008.
Correlation between self-diffusion in Si and the migration mechanisms of vacancies and self-interstitials: An atomistic study
M. Posselt, F. Gao, and H. Bracht
The migration of point defects in silicon and the corresponding atomic mobility are investigated by comprehensive classical molecular-dynamics simulations using the Stillinger-Weber potential and the Tersoff potential. In contrast to most of the previous studies both the point defect diffusivity and ... [Phys. Rev. B 78, 035208 (2008)] published Mon Jul 21, 2008.
Surface heterogeneity in Au-Ag nanoparticles probed by hyper-Rayleigh scattering
Isabelle Russier-Antoine, Guillaume Bachelier, Virginie Sabloniere, Julien Duboisset, Emmanuel Benichou et al.
Aqueous solutions of alloyed gold-silver nanoparticles, the diameter of which ranged between 15 and 50 nm, were prepared with varying molar fractions. The UV-Visible photoabsorption spectra for all solutions were dominated by a single surface-plasmon resonance, the wavelength of which was found to c ... [Phys. Rev. B 78, 035436 (2008)] published Mon Jul 21, 2008.
Radiative intersubband polaritons and reflection-absorption spectra of asymmetric microcavities with embedded multiple quantum wells
M. Zaluzny and W. Zietkowski
The usefulness of the concept of constant angle radiative intersubband polaritons in the description of the behavior of reflection-absorption spectra of bulk asymmetric microcavities with embedded multiple quantum wells is demonstrated. It is shown that a recently observed complex of the triple peak ... [Phys. Rev. B 78, 033305 (2008)] published Mon Jul 21, 2008.
Effect of Annealing on the Nb-Doped TiO[sub 2] Films Prepared by DC/RF Cosputtering
Hsiao-Chiang Yao, Ming-Chieh Chiu, Du-Cheng Tsai, Chueh-Jung Huang, and Fuh-Sheng Shieu
Nb-doped titanium oxide (TiO) thin films were deposited on glass by dc/radio-frequency (dc/rf) magnetron cosputtering, in which dc and rf were utilized for Ti and Nb targets, respectively. The coated samples were postannealed at temperatures ranging from 473 to 773 K for 1 h in ambient air. Glanci ... [J. Electrochem. Soc. 155, G173 (2008)] published Mon Jul 21, 2008.
Liquid Crystal Alignment on Plasma Beam Scanned Alkylsiloxane Self-Assembled Monolayers
K. Y. Wu, W. Y. Chen, C.-H. Wang, J. Hwang, C.-Y. Lee et al.
The octadecyltrimethoxysiloxane self-assembled monolayers (SAMs) exhibit better uniformity and smoothness on hydrogenated amorphous carbon (a-C:H) films than on indium tin oxide glasses. The liquid crystal alignment on the SAM/a-C:H can be greatly improved by Ar plasma beam scanning. The pretilt ang ... [J. Electrochem. Soc. 155, J244 (2008)] published Mon Jul 21, 2008.
Coordination environment of silicon in silica glass up to 74 GPa: An x-ray Raman scattering study at the silicon L edge
Hiroshi Fukui, Masami Kanzaki, Nozomu Hiraoka, and Yong Q. Cai
Near-edge x-ray Raman scattering (XRS) spectra of the silicon L edge have been obtained on SiO glass under compression in a diamond anvil cell up to 74 GPa. Partial densities of states (DOS's) of electrons, which the spectra reflect, have been calculated. The spectra for the glass do not show signif ... [Phys. Rev. B 78, 012203 (2008)] published Mon Jul 21, 2008.
Giant effective g-factor in Pb[sub x]Eu[sub 1 - x]Te epitaxial films
E. Heredia, P. H. de Oliveira Rappl, P. Motisuke, A. L. Gazoto, F. Iikawa et al.
We investigated PbEuTe films with x<=0.2 by magneto-optical measurements. For x~0.01, the optical emission is similar to high quality EuTe films with two narrow lines attributed to excitonic recombinations associated with magnetic polarons. For increasing x, the emission becomes dominated by a broad ... [Appl. Phys. Lett. 93, 031903 (2008)] published Mon Jul 21, 2008.
Modulus mapping of nanoscale closure variants in Ni--Mn--Ga
Yaniv Ganor and Doron Shilo
The twinned magnetic microstructure of NiMnGa ferromagnetic shape-memory alloy is investigated by high resolution nanoscale modulus mapping. A surprisingly fine near-surface nanoscale substructure of closure magnetic twin variants was observed. The lateral distance between adjacent closure variants ... [Appl. Phys. Lett. 93, 031905 (2008)] published Mon Jul 21, 2008.
From elementary steps to structural relaxation: A continuous-time random-walk analysis of a supercooled liquid
Oliver Rubner and Andreas Heuer
We show that the dynamics of supercooled liquids, analyzed from computer simulations of the binary mixture Lennard-Jones system, can be described in terms of a continuous-time random walk (CTRW). The required discretization comes from mapping the dynamics on transitions between metabasins. This yiel ... [Phys. Rev. E 78, 011504 (2008)] published Mon Jul 21, 2008.
Liquid-to-hexatic phase transition in a quasi-two-dimensional colloid system
Xinliang Xu and Stuart A. Rice
We report an analysis of the thickness dependence of the liquid-to-hexatic phase transition in a quasi-two-dimensional hard-sphere colloid system as the confining wall separation changes from 1 to 1.6 hard-sphere diameters. In our theoretical evaluation, we study the bifurcation of solutions to the ... [Phys. Rev. E 78, 011602 (2008)] published Mon Jul 21, 2008.
Erratum: On the sound field due to a moving source in a superfluid [J. Math. Phys. [bold 2][bold 0], 1409(1979)]
J. C. Murray
... [J. Math. Phys. 21, 2313 (2008)] published Mon Jul 21, 2008.
Dispersion through a flowing fluid with variable viscosity and diffusion coefficient
J. B. Shukla and R. S. Parihar
In the study of dispersion of a solute through a flowing fluid it is shown that, for a given mean velocity, the Taylor diffusion coefficient decreases as the viscosity or the thickness of the peripheral layer decreases and as the molecular diffusion coefficient of this layer increases. ... [Phys. Fluids 23, 1271 (2008)] published Mon Jul 21, 2008.
Bubble or drop distortion in a straining flow in two dimensions
Jean-Marc Vanden-Broeck and Joseph B. Keller
The distortion of a two-dimensional bubble (or drop) in a straining flow of an inviscid imcompressible fluid is examined theoretically. Far from the bubble the stream function of the flow is assumed to be alphaxy, where alpha is a constant. Within the bubble the pressure is assumed to be a constant ... [Phys. Fluids 23, 1491 (2008)] published Mon Jul 21, 2008.
[sup 4]He Adsorbed on the Outer Surface of Carbon Nanotube Bundles
M. C. Gordillo
The results of diffusion Monte Carlo calculations on the behavior of He adsorbed on the external surface of a bundle of carbon nanotubes are presented. The corrugation effects are found to be very important, making the outside part of the bundles a quite inhomogeneous substrate. No stable solid heli ... [Phys. Rev. Lett. 101, 046102 (2008)] published Mon Jul 21, 2008.
Direct Measurement of Core-Level Relaxation Dynamics on a Surface-Adsorbate System
L. Miaja-Avila, G. Saathoff, S. Mathias, J. Yin, C. La-o-vorakiat et al.
The coupling between electronic states in a surface-adsorbate system is fundamental to the understanding of many surface interactions. In this Letter, we present the first direct time-resolved observations of the lifetime of core-excited states of an atom adsorbed onto a surface. By comparing laser- ... [Phys. Rev. Lett. 101, 046101 (2008)] published Mon Jul 21, 2008.
Effects of laser irradiation on the morphology of Cu(110)
T. Brandstetter, M. Draxler, M. Hohage, P. Zeppenfeld, T. Stehrer et al.
The effects of pulsed laser irradiation on the morphology of the Cu(110) surface were investigated by means of reflectance difference spectroscopy (RDS) and spot profile analysis low-energy electron diffraction (SPA-LEED). The laser light induces surface defects (adatoms and islands) as well as subs ... [Phys. Rev. B 78, 035433 (2008)] published Fri Jul 18, 2008.
Bidirectional wavelength tuning of individual semiconductor quantum dots in a flexible rolled-up microtube
S. Mendach, S. Kiravittaya, A. Rastelli, M. Benyoucef, R. Songmuang et al.
We consider a pair of artificial atoms with different ground-state energies. By means of finite element calculations, we predict that the ground-state energies can be tuned into resonance if the artificial atoms are placed into a flexible ring structure, which is elastically deformed by an external ... [Phys. Rev. B 78, 035317 (2008)] published Fri Jul 18, 2008.
Ergodicity and slowing down in glass-forming systems with soft potentials: No finite-temperature singularities
Jean-Pierre Eckmann and Itamar Procaccia
The aim of this paper is to discuss some basic notions regarding generic glass-forming systems composed of particles interacting via soft potentials. Excluding explicitly hard-core interaction, we discuss the so-called glass transition in which a supercooled amorphous state is formed, accompanied by ... [Phys. Rev. E 78, 011503 (2008)] published Fri Jul 18, 2008.
Regular and chaotic states in a local map description of sheared nematic liquid crystals
S. M. Kamil, Sudeshna Sinha, and Gautam I. Menon
We propose and study a local map capable of describing the full variety of dynamical states, ranging from regular to chaotic, obtained when a nematic liquid crystal is subjected to a steady shear flow. The map is formulated in terms of a quaternion parametrization of rotations of the local frame des ... [Phys. Rev. E 78, 011706 (2008)] published Fri Jul 18, 2008.
Structural domain and finite-size effects of the antiferromagnetic S = 1/2 honeycomb lattice in InCu[sub 2/3]V[sub 1/3]O[sub 3]
A. Moller, U. Low, T. Taetz, M. Kriener, G. Andre et al.
The compound InCuVO has been studied by spectroscopy in the IR, near-infrared, and visible regions. X-ray and neutron diffraction indicate two-dimensional (2D) structural order of magnetic Cu (S=1/2) ions on a honeycomb lattice with nonmagnetic V ions complementing the hexagonal layer. Superstructur ... [Phys. Rev. B 78, 024420 (2008)] published Fri Jul 18, 2008.
Modeling arrested cluster growth in quenched nanoparticle solutions
I. Podariu, Hao Yan, C. M. Sorensen, and A. Chakrabarti
We have carried out numerical simulations on a model of phase separation in a binary mixture in the presence of a third, surface-active component. Based on this model we study phase separation in a quenched solution of gold nanoparticles with dodecane thiol ligands in a mixed solvent of butanone and ... [J. Chem. Phys. 129, 034706 (2008)] published Fri Jul 18, 2008.
Fundamental measure density functional theory studies on the freezing of binary hard-sphere and Lennard-Jones mixtures
Vadim B. Warshavsky and Xueyu Song
Free energies and correlation functions of liquid and solid hard-sphere (HS) mixtures are calculated using the fundamental measure density functional theory. Using the thermodynamic perturbation theory the free energies of solid and liquid Lennard-Jones (LJ) mixtures are obtained from correlation fu ... [J. Chem. Phys. 129, 034506 (2008)] published Fri Jul 18, 2008.
Change in the interfacial reaction of Hf-silicate film as a function of thickness and stoichiometry
M.-H. Cho, C. Y. Kim, K. Moon, K. B. Chung, C. J. Yim et al.
Medium energy ion scattering and high-resolution transmission electron microscopy are used to investigate the depth of the interfacial reaction of Hf-silicate film. The interfacial reaction is critically affected by the film thickness and the mole fraction of HfO in silicate film. The interfacial co ... [J. Chem. Phys. 129, 034705 (2008)] published Fri Jul 18, 2008.
The microscopic structure of an exactly solvable model binary solution that exhibits two closed loops in the phase diagram
Radu P. Lungu and Dale A. Huckaby
An exactly solvable lattice model describing a binary solution is considered where rodlike molecules of types AA and BB cover the links of a honeycomb lattice, the neighboring molecular ends having three-body and orientation-dependent bonding interactions. At phase coexistence of AA-rich and BB-rich ... [J. Chem. Phys. 129, 034505 (2008)] published Fri Jul 18, 2008.
Raman scattering in hcp rare gas solids under pressure
Yu. A. Freiman, Alexander F. Goncharov, S. M. Tretyak, A. Grechnev, John S. Tse et al.
We present Raman measurements of hcp rare gas solids (RGSs) at megabar pressures together with lattice dynamics calculations. The E phonon was measured in Xe up to metallization near 135 GPa and in Ar up to 58 GPa. A comparative analysis of first-principles and semiempirical calculations shows that ... [Phys. Rev. B 78, 014301 (2008)] published Fri Jul 18, 2008.
The role of the beta-phase content on the stimulated emission of poly(9,9-dioctylfluorene) thin films
M. Anni
We investigated the optical gain properties of poly(9,9-dioctylfluorene) thin films as a function of the beta-phase content. We demonstrate that the product between the gain cross section and the excited state lifetime of the beta-phase is about 3.2 times larger than the glassy-phase one, indicating ... [Appl. Phys. Lett. 93, 023308 (2008)] published Fri Jul 18, 2008.
Morphological and Photoelectrochemical Properties of ALD TiO[sub 2] Films
Hsyi-En Cheng and Chia-Chuan Chen
TiO films were grown by atomic layer deposition (ALD) at 200500 degrees C with TiCl and HO as gas sources. The relationships among deposition temperature, microstructure, and photoelectrochemical properties were investigated. The results showed that the crystalline form is anatase at deposition temp ... [J. Electrochem. Soc. 155, D604 (2008)] published Fri Jul 18, 2008.
Characterization of Gallium Nitride Grown on Patterned Sapphire Substrate with Shallow U-Shaped Stripe Grooves
Ko-Tao Lee, Yeeu-Chang Lee, and Jeng-Yang Chang
A patterned sapphire substrate with shallow U-shaped stripe grooves along the <11[overline 2]0> direction prepared by chemical wet etching was used for the growth of high-quality gallium-nitride-based epilayers without air gap formation. From characterization by scanning electron microscopy, transmi ... [J. Electrochem. Soc. 155, H673 (2008)] published Fri Jul 18, 2008.
Competitive Adsorption Between Bis(3-sodiumsulfopropyl disulfide) and Polyalkylene Glycols on Copper Electroplating
Chi-Cheng Hung, Ying-Lang Wang, Wen-Hsi Lee, and Shih-Chieh Chang
In semiconductor copper (Cu) metallization, external organic additives including bis(3-sodiumsulfopropyl disulfide) (SPS) and polyalkylene glycols (PAG) are necessary and widely used to improve the gap-fill capability of Cu electroplating for high-aspect-ratio features. In this study, the interactio ... [J. Electrochem. Soc. 155, H669 (2008)] published Fri Jul 18, 2008.
The role of the beta-phase content on the stimulated emission of poly(9,9-dioctylfluorene) thin films
M. Anni
We investigated the optical gain properties of poly(9,9-dioctylfluorene) thin films as a function of the beta-phase content. We demonstrate that the product between the gain cross section and the excited state lifetime of the beta-phase is about 3.2 times larger than the glassy-phase one, indicating ... [Appl. Phys. Lett. 93, 023308 (2008)] published Fri Jul 18, 2008.
The influence of stoichiometry on the structural stability and on the optical emission of erbium silicate thin films
R. Lo Savio, M. Miritello, A. M. Piro, F. Priolo, and F. Iacona
We report the effects of thermal annealing performed in N or O ambient at 1200 degrees C on the structural and optical properties of Er silicate films having different compositions (ErSiO, ErSiO, and their mixture). We demonstrate that the chemical composition of the stoichiometric films is preser ... [Appl. Phys. Lett. 93, 021919 (2008)] published Fri Jul 18, 2008.
Electron spin resonance studies of P and B codoped Si nanocrystals
Kazuyoshi Fujio, Minoru Fujii, Kazuaki Sumida, Shinji Hayashi, Masashi Fujisawa et al.
P- and/or B-doped Si nanocrystals (Si-ncs) embedded in glass matrices were studied by electron spin resonance (ESR) spectroscopy to investigate the origin of strong room-temperature photoluminescence (PL) of n- and p-type impurities codoped Si-ncs below the band-gap energy of bulk Si crystals. It wa ... [Appl. Phys. Lett. 93, 021920 (2008)] published Fri Jul 18, 2008.
Length dependent behavior of a carbon nanotube interacting at liquid-air interface
Edward D. de Asis, Jr., You Li, Riichiro Ohta, Alex Austin, Joseph Leung et al.
We report the irreversible structural failure of individual multiwalled carbon nanotube (MWNT) tips after water submersion. We used 11 individual MWNTs with varying geometries and showed length dependent MWNT failure with scanning electron microscopy. Shorter MWNTs are more likely to survive penetra ... [Appl. Phys. Lett. 93, 023129 (2008)] published Fri Jul 18, 2008.
Examining the terahertz signal from a photoexcited biased semiconductor superlattice for evidence of gain
A. Lisauskas, M. M. Dignam, N. V. Demarina, E. Mohler, and H. G. Roskos
We present a careful analysis of the coherent terahertz emission from an undoped biased semiconductor superlattice excited via an ultrashort optical pulse. We use both a semiclassical model and a fully quantum-mechanical model that includes the excitation process and excitonic effects to analyze emi ... [Appl. Phys. Lett. 93, 021122 (2008)] published Fri Jul 18, 2008.
Below-Gap Excitation of pi-Conjugated Polymer-Fullerene Blends: Implications for Bulk Organic Heterojunction Solar Cells
T. Drori, C.-X. Sheng, A. Ndobe, S. Singh, J. Holt et al.
We used a variety of optoelectronic techniques such as broadband fs transient and cw photomodulation spectroscopies, electroabsorption, and short-circuit photocurrent in bulk heterojunctions organic solar cells for studying the photophysics in pi-conjugated polymer-fullerene blends with below-gap ex ... [Phys. Rev. Lett. 101, 037401 (2008)] published Fri Jul 18, 2008.
Poynor et al. Reply:
Adele Poynor, Liang Hong, Ian K. Robinson, Steve Granick, Paul A. Fenter et al.
A Reply to the Comment by Benjamin M. Ocko, Ali Dhinojwala, and Jean Daillant. ... [Phys. Rev. Lett. 101, 039602 (2008)] published Fri Jul 18, 2008.
Nature of the Structural Transformations in B[sub 2]O[sub 3] Glass under High Pressure
V. V. Brazhkin, Y. Katayama, K. Trachenko, O. B. Tsiok, A. G. Lyapin et al.
We study high-pressure polyamorphism of BO glass using x-ray diffraction up to 10 GPa in the 300700 K temperature range, in situ volumetric measurements up to 9 GPa, and first-principles simulations. Under pressure, glass undergoes two-stage transformations including a gradual increase of the first ... [Phys. Rev. Lett. 101, 035702 (2008)] published Fri Jul 18, 2008.
Comment on ``How Water Meets a Hydrophobic Surface''
Benjamin M. Ocko, Ali Dhinojwala, and Jean Daillant
A Comment on the Letter by Adele Poynor et al., Phys. Rev. Lett. 97, 266101 (2006). The authors of the Letter offer a Reply. ... [Phys. Rev. Lett. 101, 039601 (2008)] published Fri Jul 18, 2008.
Statistical Mechanics of Steiner Trees
M. Bayati, C. Borgs, A. Braunstein, J. Chayes, A. Ramezanpour et al.
The minimum weight Steiner tree (MST) is an important combinatorial optimization problem over networks that has applications in a wide range of fields. Here we discuss a general technique to translate the imposed global connectivity constrain into many local ones that can be analyzed with cavity equ ... [Phys. Rev. Lett. 101, 037208 (2008)] published Fri Jul 18, 2008.
Excited-State Molecular Vibration Observed for a Probe Pulse Preceding the Pump Pulse by Real-Time Optical Spectroscopy
Takayoshi Kobayashi, Juan Du, Wei Feng, and Katsumi Yoshino
It is shown experimentally that the absorbance change observed in the negative time range, where probe pulse precedes pump pulse in real-time vibrational spectroscopy is induced only by the excited-state wave-packet motion as theoretically expected. Coherent molecular vibration of a polymer in the e ... [Phys. Rev. Lett. 101, 037402 (2008)] published Fri Jul 18, 2008.
An Examination of Fatigue Initiation Mechanisms in Thin 35Co-35Ni-20Cr-10Mo Medical Grade Wires
Jeremy E. Schaffer
Knowledge of the intrinsic defect size distribution, surface grain size distribution, and prior deformation history are important factors in determining fatigue crack initiation mechanisms and total life variability in thin, metallic, medical grade wires. The ASTM F562 alloy system is used extensive ... [J. ASTM Int. 5, 101567 (2008)] published Fri Jul 18, 2008.
Epitaxial La[sub 0.5]Sr[sub 0.5]CoO[sub 3] thin films: Structure, magnetism, and transport
M. A. Torija, M. Sharma, M. R. Fitzsimmons, M. Varela, and C. Leighton
LaSrCoO has received considerable attention in bulk form. This is due to interest in the fundamental magnetic properties (spin-state transitions and magnetic phase separation) as well as potential applications in ferroelectric memory and solid-oxide fuel cells. The structure and properties in thin f ... [J. Appl. Phys. 104, 023901 (2008)] published Fri Jul 18, 2008.
Effect of antimony incorporation on the density, shape, and luminescence of InAs quantum dots
J. F. Chen, C. H. Chiang, Y. H. Wu, L. Chang, and J. Y. Chi
This work investigates the surfactant effect on exposed and buried InAs quantum dots (QDs) by incorporating Sb into the QD layers with various Sb beam equivalent pressures (BEPs). Secondary ion mass spectroscopy shows the presence of Sb in the exposed and buried QD layers with the Sb intensity in th ... [J. Appl. Phys. 104, 023509 (2008)] published Fri Jul 18, 2008.
Frank dislocation loops in HgTe/CdTe superlattices on CdTe/Si(211)B substrates
L. F. Fu, N. L. Okamoto, M. F. Chi, N. D. Browning, H. S. Jung et al.
The defect structures in HgTe/CdTe superlattices (SLs) on CdTe/Si(211)B substrates grown by molecular-beam epitaxy have been investigated using (scanning) transmission electron microscopy and electron energy loss spectroscopy. Straight Hg-rich defects perpendicular to the SLs have been observed near ... [J. Appl. Phys. 104, 023104 (2008)] published Fri Jul 18, 2008.
High cluster formation tendency in Co implanted ZnO
K. Potzger, K. Kuepper, Q. Xu, S. Zhou, H. Schmidt et al.
ZnO(0001) single crystals have been implant doped with a maximum of 5 at. % of Co at low temperatures. While as-implanted crystals do not show ferromagnetic properties, postimplantation annealing leads to the transformation of the implanted Co ions into small metallic clusters giving rise to a pron ... [J. Appl. Phys. 104, 023510 (2008)] published Fri Jul 18, 2008.
Crystallization and shear modulus of a forming biopolymer film determined by in situ x-ray diffraction and ultrasound reflection methods
Marko Peura, Timo Karppinen, Annemai Soovre, Ari Salmi, Maija Tenkanen et al.
The structure and the rigidity of a forming biopolymer film were determined using concurrent x-ray diffraction and ultrasonic reflection measurements. Film formation of a xylan solution (de-ionized water, 10 g/l xylan, 4 g/l glycerol) was studied during water evaporation at 24(2) degrees C, 37(5 ... [J. Appl. Phys. 104, 023513 (2008)] published Fri Jul 18, 2008.
POLIR: Polarizable, flexible, transferable water potential optimized for IR spectroscopy
Parminder K. Mankoo and Thomas Keyes
A polarizable, flexible and transferable potential for water, POLIR, is presented. In addition to providing a good description of the usual structural and kinetic properties, POLIR correctly describes the vibrational frequencies, absolute infrared intensities, and HOH angle in clusters, liquid water ... [J. Chem. Phys. 129, 034504 (2008)] published Thu Jul 17, 2008.
Structure versus electron effects in the growth mode of pentacene on metal-induced Si(111)-sqrt(3) x sqrt(3) surfaces
Jing Teng, Jiandong Guo, Kehui Wu, and Enge Wang
The growth of pentacene films on different metal (Ga, Pb, Bi, Ag) induced Si(111)-(sqrt(3) x sqrt(3))R30 degrees surfaces is investigated by scanning tunneling microscopy. On surfaces with high atomic surface roughness, such as Ga/Si-sqrt(3), beta-Pb/Si-sqrt(3), and alpha-Bi/Si-sqrt(3), pentacene f ... [J. Chem. Phys. 129, 034703 (2008)] published Thu Jul 17, 2008.
Incommensurability and atomic structure of c(2 x 2)N/Cu(100): A scanning tunneling microscopy study
T. Choi, C. D. Ruggiero, and J. A. Gupta
We use a scanning tunneling microscope operating in a low-temperature ultrahigh vacuum environment to study the atomic structure of single layer films of CuN grown on Cu(100). The c(2 x 2) lattice of CuN is incommensurate, with a lattice constant of 0.3720.001 nm that is 3% larger than the bare Cu( ... [Phys. Rev. B 78, 035430 (2008)] published Thu Jul 17, 2008.
Erratum: Site-specific force-distance characteristics on NaCl(001): Measurements versus atomistic simulations [Phys. Rev. B [bold 74], 245426 (2006)]
M. A. Lantz, R. Hoffmann, A. S. Foster, A. Baratoff, H. J. Hug et al.
... [Phys. Rev. B 78, 039901 (2008)] published Thu Jul 17, 2008.
Shock-induced shear bands in an energetic molecular crystal: Application of shock-front absorbing boundary conditions to molecular dynamics simulations
M. J. Cawkwell, Thomas D. Sewell, Lianqing Zheng, and Donald L. Thompson
The response of the energetic molecular crystal cyclotrimethylene trinitramine (RDX) to the propagation of planar shock waves normal to (100) has been studied using large-scale molecular dynamics simulations that employ an accurate and transferable nonreactive potential. The propagation of the shock ... [Phys. Rev. B 78, 014107 (2008)] published Thu Jul 17, 2008.
Interfacial elastic properties between a-Si and c-Si
Pier Luca Palla, Stefano Giordano, and Luciano Colombo
Interfaces between different media represent the most common structure in composite and complex materials, e.g., with applications in microelectronics and photovoltaics. We analyze the elastic properties of the -Si/ac-Si interface, which involves two completely different atomic structures. We prove ... [Phys. Rev. B 78, 012105 (2008)] published Thu Jul 17, 2008.
Parallel scanning tunneling microscopy imaging of low dimensional nanostructures
Barnim A. Janta-Polczynski, Jorge I. Cerda, Gabriel Ethier-Majcher, Konstantinos Piyakis, and Alain Rochefort
A first generation of parallel scanning tunneling microscopy (STM) simulator has been developed to accelerate the production of high quality STM images. An efficient master-slave parallel scheme has been constructed specially suited for large scale problems in which the amount of data communications ... [J. Appl. Phys. 104, 023702 (2008)] published Thu Jul 17, 2008.
Phonon sideband recombination kinetics in single quantum dots
M. Abbarchi, M. Gurioli, A. Vinattieri, S. Sanguinetti, M. Bonfanti et al.
We report an experimental study on the recombination kinetics of single strain-free GaAs quantum dots (QDs) grown by modified droplet epitaxy. The different bands composing the single quantum dot emission line at high temperature show identical dynamics, proving the common origin of all contribution ... [J. Appl. Phys. 104, 023504 (2008)] published Thu Jul 17, 2008.
Coherency effects in nanobeam x-ray diffraction analysis
Hanfei Yan, Ozgur Kalenci, I. Cevdet Noyan, and Jorg Maser
We describe the evolution of the x-ray scattering pattern which forms on an area detector when a divergent, coherent nanobeam is diffracted from a perfect or weakly deformed single crystal. We show that the scattering can be considered as virtual diffraction from an angular aperture in reciprocal sp ... [J. Appl. Phys. 104, 023506 (2008)] published Thu Jul 17, 2008.
On the anisotropic thermal conductivity of magnetorheological suspensions
Benjamin N. Reinecke, Jerry W. Shan, Karl K. Suabedissen, and Anna S. Cherkasova
The thermal conductivity of an iron-based magnetorheological suspension is experimentally investigated for varying particle volume fractions and magnetic-field strengths. Under a magnetic field, the thermal-conductivity component in the field direction increases significantly (by 100% in one case), ... [J. Appl. Phys. 104, 023507 (2008)] published Thu Jul 17, 2008.
Optical intensity analyses of Er[sup 3+]:YAlO[sub 3]
Dhiraj K. Sardar, Sreerenjini Chandrasekharan, Kelly L. Nash, and John B. Gruber
Analyses of the optical absorption and emission intensities are performed on Er ions doped into yttrium orthoaluminate YAlO to assess this material as a laser source. The JuddOfelt model is applied to the room temperature absorption intensities of Er in YAlO to obtain the phenomenological intensity ... [J. Appl. Phys. 104, 023102 (2008)] published Thu Jul 17, 2008.
Annealing effect on the luminescence properties of BaZrO[sub 3]:Yb[sup 3+] microcrystals
J. Oliva, E. De la Rosa, L. A. Diaz-Torres, P. Salas, and C. Angeles-Chavez
Yb-doped barium zirconate (BaZrO:Yb) was synthesized by a hydrothermal method at 100 degrees C. It presents a cubic perovskite crystalline phase, which is stable between 100 and 100 degrees C. Upon increasing the annealing temperature, two major changes are observed. (1) The near infrared (NIR) ab ... [J. Appl. Phys. 104, 023505 (2008)] published Thu Jul 17, 2008.
Modeling optical transitions of Er[sup 3+](4f[sup 11]) in C[sub 2] and C[sub 3i] sites in polycrystalline Y[sub 2]O[sub 3]
John B. Gruber, Kelly L. Nash, Dhiraj K. Sardar, Uygun V. Valiev, Nikolay Ter-Gabrielyan et al.
The optical properties of Er in polycrystalline (ceramic), and nanocrystalline forms of cubic (bixbyite) yttrium oxide are modeled based on the absorption spectra obtained between 400 and 1700 nm and the fluorescence spectra observed between 1500 and 1670 nm. Both spectra were obtained at 8 K. The o ... [J. Appl. Phys. 104, 023101 (2008)] published Thu Jul 17, 2008.
Transition layers at the SiO[sub 2]/SiC interface
Tsvetanka Zheleva, Aivars Lelis, Gerd Duscher, Fude Liu, Igor Levin et al.
The electrical performance of SiC-based microelectronic devices is strongly affected by the densities of interfacial traps introduced by the chemical and structural changes at the SiO/SiC interface during processing. We analyzed the structure and chemistry of this interface for the thermally grown S ... [Appl. Phys. Lett. 93, 022108 (2008)] published Thu Jul 17, 2008.
X-ray absorption in GaGdN: A study of local structure
G. Martinez-Criado, O. Sancho-Juan, N. Garro, J. A. Sans, A. Cantarero et al.
In this study, we report on the incorporation of dilute Gd amounts into GaN films grown by molecular beam epitaxy. A combination of x-ray fluorescence with x-ray absorption spectroscopic techniques enabled us to examine not only the distribution of rare earth atoms in the GaN matrix but also the sho ... [Appl. Phys. Lett. 93, 021916 (2008)] published Thu Jul 17, 2008.
Charge carrier induced lattice strain and stress effects on As activation in Si
Chihak Ahn and Scott T. Dunham
We studied lattice expansion coefficient due to As using density functional theory with particular attention to separating the impact of electrons and ions. Based on As deactivation mechanism under equilibrium conditions, the effect of stress on As activation is predicted. We find that biaxial stres ... [Appl. Phys. Lett. 93, 022112 (2008)] published Thu Jul 17, 2008.
Optical properties of (GeTe, Sb[sub 2]Te[sub 3]) pseudobinary thin films studied with spectroscopic ellipsometry
Jun-Woo Park, Seoung Ho Baek, Tae Dong Kang, Hosun Lee, Youn-Seon Kang et al.
The authors measure the dielectric functions of (GeTe, SbTe) pseudobinary thin films by using spectroscopic ellipsometry. By using standard critical point model, they obtained the optical transition (critical point) energies of the amorphous (crystalline) thin films. The optical (indirect band) gap ... [Appl. Phys. Lett. 93, 021914 (2008)] published Thu Jul 17, 2008.
Paramagnetic point defects at SiO[sub 2]/nanocrystalline Si interfaces
A. Stesmans, M. Jivanescu, S. Godefroo, and M. Zacharias
A K- and Q-band electron spin resonance study, combining two detection modes, on structures composed of Si nanoparticles (~2 nm across) embedded in a SiO matrix obtained by annealing of SiO/SiO superstructures unveils the observed principal Si dangling bond signal as solely comprised of the intrins ... [Appl. Phys. Lett. 93, 023123 (2008)] published Thu Jul 17, 2008.
Polar steric interactions for [sans-serif V]-shaped molecules
Fulvio Bisi, Riccardo Rosso, Epifanio G. Virga, and Georges E. Durand
We consider the effect of shape polarity in the excluded-volume interaction between V-shaped polar particles in orientationally ordered phases. We show that the polar component of the steric interaction between these polar particles, large enough in two space dimensions, can also become important in ... [Phys. Rev. E 78, 011705 (2008)] published Thu Jul 17, 2008.
Effect of Fluctuations in the Brush Conformation on the Interaction Between Polymer Brushes in a Good Solvent
Yan Xing Shen and Jen Fin Lin
This study presents a novel approach for analyzing the interaction between two parallel surfaces grafted with polymer brushes in a good solvent. In the proposed approach, molecular dynamics simulations are performed to establish the mean brush height and the standard deviation of the brush height di ... [J. Appl. Mech. 75, 051009 (2008)] published Thu Jul 17, 2008.
Topological Defects in Spherical Nematics
Homin Shin, Mark J. Bowick, and Xiangjun Xing
We study the organization of topological defects in a system of nematogens confined to the two-dimensional sphere (S). We first perform Monte Carlo simulations of a fluid system of hard rods (spherocylinders) living in the tangent plane of S. The sphere is adiabatically compressed until we reach a j ... [Phys. Rev. Lett. 101, 037802 (2008)] published Thu Jul 17, 2008.
Infinite Randomness Fixed Point of the Superconductor-Metal Quantum Phase Transition
Adrian Del Maestro, Bernd Rosenow, Markus Muller, and Subir Sachdev
We examine the influence of quenched disorder on the superconductor-metal transition, as described by a theory of overdamped Cooper pairs which repel each other. The self-consistent pairing eigenmodes of a quasi-one-dimensional wire are determined numerically. Our results support the recent proposal ... [Phys. Rev. Lett. 101, 035701 (2008)] published Thu Jul 17, 2008.
Dynamic Singularity in Multicomponent Glass-Forming Metallic Liquids
S. M. Chathoth, B. Damaschke, M. M. Koza, and K. Samwer
In the liquid state, glass-forming NiNb and NiNbSn alloys exhibit an extraordinarily high packing fraction. The self-correlation functions measured using quasielastic neutron scattering clearly show the slowing down of microscopic dynamics with an increase in packing fraction. The self-diffusivity i ... [Phys. Rev. Lett. 101, 037801 (2008)] published Thu Jul 17, 2008.
Phase Transition in the Three-State Potts Antiferromagnet on the Diced Lattice
Roman Kotecky, Jesus Salas, and Alan D. Sokal
We prove that the 3-state Potts antiferromagnet on the diced lattice (dual of the kagome lattice) has entropically driven long-range order at low temperatures (including zero). We then present Monte Carlo simulations, using a cluster algorithm, of the 3-state and 4-state models. The 3-state model ha ... [Phys. Rev. Lett. 101, 030601 (2008)] published Thu Jul 17, 2008.