publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2006-03-30 | Poisson's ratio in cubic materials | Expressions are given for the maximum and minimum values of Poisson's ratio
$\nu$ for materials with cubic symmetry. Values less than -1 occur if and only
if the maximum shear modulus is associated with the cube axis and is at least
25 times the value of the minimum shear modulus. Large values of $|\nu|$ occur
in direc... | 0603820v1 |
2006-04-01 | Mechanism for modulated structures in Ni-Mn-Ga: An EXAFS Study | The local atomic structure of Ni-Mn-Ga alloys was explored using Mn and Ga
K-edge extended X-ray fine structure (EXAFS) measurement. The changes occuring
in the L1$_0$ sub-cell of the martensitic unit cell and the bond lengths
obtained from the analysis enables us to propose a scheme for the structural
distortions resp... | 0604010v2 |
2006-04-08 | Lattice Misfit Measurement in Inconel 625 by X-Ray Diffraction Technique | Determination of lattice misfit and microstructural parameters of the
coherent precipitates in Ni based alloy Inconel-625 is a challenging problem as
their peaks are completely overlapping among themselves and also with the
matrix. We have used a novel X-ray diffraction technique on the bulk samples of
Inconel 625 at d... | 0604222v1 |
2006-04-08 | Multiscale Entropy Analysis of the Portevin-Le Chatelier Effect in an Al-2.5%Mg Alloy | The complexity of the Portevin-Le Chatelier effect in Al-2.5%Mg
polycrystalline samples subjected to uniaxial tensile tests is quantified.
Multiscale entropy analysis is carried out on the stress time series data
observed during jerky flow to quantify the complexity of the distinct
spatiotemporal dynamical regimes. It ... | 0604227v1 |
2006-05-23 | Interplay between diffusive and displacive phase transformations: TTT diagrams and microstructures | Materials which can undergo extremely fast displacive transformations as well
as very slow diffusive transformations are studied using a Ginzburg-Landau
framework to understand the physics behind microstructure formation and
time-temperature-transformation (TTT) diagrams. This simple model captures the
essential featur... | 0605577v1 |
2006-06-28 | Evolution of superconductivity in Pr$_{1-x}$La$_{x}$Os$_{4}$Sb$_{12}$: Upper critical field measurements | Measurements of the upper critical field $H_{c2}$ near $T_c$ of Pr$_{1-
x}$La$_{x}$Os$_{4}$Sb$_{12}$ were performed by specific heat. A positive
curvature in $H_{c2}$ versus $T$ was observed in samples and concentrations
exhibiting two superconducting transitions. These results argue against this
curvature being due to... | 0606730v1 |
2006-07-04 | Microscopic Characterization of the L10-FePt Nanoparticles Synthesized by the SiO2-Nanoreactor Method | We investigated magnetic properties of the L10-FePt nanoparticles synthesized
by the SiO2-nanoreactor method by means of Moessbauer spectroscopy from the
microscopic point of view. Almost all of the nanoparticles were revealed to
have nearly the same Moessbauer hyperfine parameters as those of the bulk
L10-FePt alloy, ... | 0607071v1 |
2006-07-16 | Lattice and elastic constants of titanium-niobium monoborides containing aluminum and vanadium | First-principles electronic-structure computes the lattice and elastic
constants of single-crystal TiB and NbB and changes with Nb, Ti, Al, and V
solutes. The data is built into an interpolation formula for lattice and
elastic constants of the quartenary (TiNbAlV)B with dilute Al and V
concentrations. The lattice and e... | 0607398v1 |
2006-07-17 | Mott and Band Insulator Transitions in the Binary Alloy Hubbard Model | We use determinant Quantum Monte Carlo simulations and exact diagonalization
to explore insulating behavior in the Hubbard model with a bimodal distribution
of randomly positioned local site energies. From the temperature dependence of
the compressibility and conductivity, we show that gapped, incompressible Mott
insul... | 0607427v2 |
2006-08-25 | Melting of alloys along the inter-phase boundaries in eutectic and peritectic systems | We discuss a simple model of the melting kinetics along the solid-solid
interface in eutectic and peritectic systems. The process is controlled by the
diffusion inside the liquid phase and the existence of a triple junction is
crucial for the velocity selection problem. Using the lubrication approximation
for the diffu... | 0608556v1 |
2006-10-06 | Significant enhancement of room temperature ferromagnetism in surfactant coated polycrystalline Mn doped ZnO particles | We report a surfactant assisted synthesis of Mn doped ZnO polycrystalline
samples showing robust room temperature ferromagnetism as characterized by
X-ray diffraction analysis, Transmission Electron Microscopy, Electron
Paramagnetic Resonance and DC magnetization mearurements. This surfactant
assisted synthesis method,... | 0610170v1 |
2006-10-30 | Magnetic state and electronic structure of plutonium from ``first principles'' calculations | The goal to describe plutonium phases from ``first principles'' calculation
methods is complicated by the problem of 5f-electrons localization. While for
early actinides (Th, U,Np) standard DFT (Density Functional Theory) description
with itinerant 5f-electrons works well for late actinides (Am, Cm) DFT
calculations wi... | 0610829v1 |
2007-01-24 | Random Kondo Alloys | The interplay between the Kondo effect and disorder is studied. This is done
by applying a matrix coherent potential approximation (CPA) and treating the
Kondo interaction on a mean-field level. The resulting equations are shown to
agree with those derived by the dynamical mean-field method (DMFT). By applying
the form... | 0701598v1 |
2007-03-11 | Hole states in wide band-gap diluted magnetic semiconductors and oxides | Puzzling disagreement between photoemission and optical findings in
magnetically doped GaN and ZnO is explained within a generalized alloy theory.
The obtained results show that the strong coupling between valence-band holes
and localized spins gives rise to a mid-gap Zhang-Rice-like state, to a sign
reversal of the ap... | 0703278v1 |
2007-03-29 | Thermo-reversible permanent magnets in the quasi-binary GdCo5-xCux system | Ferrimagnetic GdCo5-xCux alloys exhibiting the effect of Gd- and
3d-sublattice magnetization compensation at defined temperatures were studied
with respect to their use as thermo-reversible permanent magnets (PM). Coercive
fields 0Hc in the range 0.3 to 1.6 T were measured for annealed single
crystals with x = ... | 0703775v1 |
2006-05-24 | Knowledge Flow Analysis for Security Protocols | Knowledge flow analysis offers a simple and flexible way to find flaws in
security protocols. A protocol is described by a collection of rules
constraining the propagation of knowledge amongst principals. Because this
characterization corresponds closely to informal descriptions of protocols, it
allows a succinct and n... | 0605109v1 |
2000-06-29 | First results from phi -> KL KS decays with the KLOE detector | The KLOE experiment has collected 2.4 1/pb of integrated luminosity during
the commissioning of the DAFNE phi-factory in 1999. The performance of the
detector has been studied using phi -> KL KS decays collected during this
period, yielding also first measurements of relevant K parameters such as
masses and lifetimes. ... | 0006035v1 |
1995-08-25 | Expulsion of Magnetic Flux Lines from the Growing Superconducting Core of a Magnetized Quark Star | The expulsion of magnetic flux lines from a growing superconducting core of a
quark star has been investigated. The idea of impurity diffusion in molten
alloys and an identical mechanism of baryon number transport from hot
quark-gluon-plasma phase to hadronic phase during quark-hadron phase transition
in the early univ... | 9508384v2 |
2001-06-04 | Complex poles and oscillatory screened potential in QED plasmas | We discuss the mechanism for the oscillatory behavior of the static
interparticle potential in a degenerate electron plasma. This behavior,
observed in metallic alloys, is commonly referred to as 'Friedel oscillations',
and its origin associated to the Kohn singularity. We show that, although this
interpretation is ade... | 0106032v1 |
2000-10-14 | Localization for One Dimensional, Continuum, Bernoulli-Anderson Models | We use scattering theoretic methods to prove strong dynamical and exponential
localization for one dimensional, continuum, Anderson-type models with singular
distributions; in particular the case of a Bernoulli distribution is covered.
The operators we consider model alloys composed of at least two distinct types
of ra... | 0010016v1 |
2004-08-06 | On the Lipschitz continuity of the integrated density of states for sign-indefinite potentials | The present paper is devoted to the study of spectral properties of random
Schroedinger operators. Using a finite section method for Toeplitz matrices, we
prove a Wegner estimate for some alloy type models where the single site
potential is allowed to change sign. The results apply to the corresponding
discrete model, ... | 0408013v3 |
2005-09-12 | Lifshitz Tails in Constant Magnetic Fields | We consider the 2D Landau Hamiltonian $H$ perturbed by a random alloy-type
potential, and investigate the Lifshitz tails, i.e. the asymptotic behavior of
the corresponding integrated density of states (IDS) near the edges in the
spectrum of $H$. If a given edge coincides with a Landau level, we obtain
different asympto... | 0509022v1 |
1994-11-09 | Reciprocal Space Analysis of Short Range Order Intensities by the Cluster Variation Method | A reciprocal space formulation of the Cluster Variation is used in order to
extract effective pair interactions in alloys from experimental short-range
order diffuse intensities. The method is applied to the analysis of the short
range order contribution to the neutron diffuse scattering of a $Fe-19.5 {\%}
Al$ single c... | 9411002v1 |
1995-06-13 | Complex ion formation in liquid Ag-Se alloys | Ab initio molecular dynamics simulations are used to investigate the
structure and electronic properties of the liquid Ag-Se system at three
compositions. The realism of the simulations is demonstrated by comparison with
diffraction data for the stoichiometric case Ag$_2$Se. As the Se content is
increased beyond the st... | 9506002v2 |
1999-08-17 | Characterisation of Fourteenth-Century Bell-Casting Pit in Old Town Hall Sibiu, Romania | In this work we have made an analytical investigation by neutron activation
analysis and X-ray fluorescence of a number of pieces found on the two hearths
and the slag layer discovered at the Old Town Hall from Sibiu, Romania and some
bells from the surrounding region of Sibiu. The elemental analyses suggest the
fact t... | 9908006v1 |
1993-05-21 | Nonequilibrium Phenomena in Liquid Crystals | This paper summarizes a talk presented at the April NATO ASI on
Spatiotemporal Chaos in Complex Fluids, in Santa Fe, NM. The paper gives
reasons that make complex fluids good material systems for conducting
experiments on pattern formation and other nonequilibrium phenomena. Much of
the discussion focuses on the differ... | 9305009v1 |
1998-10-27 | Symmetry Adaptation Techniques in n-Photon Absorption Spectroscopy | We present some recent progress achieved in the application of symmetry
adaptation techniques to n-photon absorption spectroscopy of rare earth ions in
finite symmetry. More specifically, this work is concerned with the
determination of the intensity of n-photon transitions between Stark levels
(rather than J levels) o... | 9810055v1 |
2004-12-17 | Electron Conditioning of Technical Aluminium Surfaces: Effect on the Secondary Electron Yield | The effect of electron conditioning on commercially aluminium alloys 1100 and
6063 were investigated. Contrary to the assumption that electron conditioning,
if performed long enough, can reduce and stabilize the SEY to low values ($\leq
1.3$, value of many pure elements), the SEY of aluminium did not go lower than
1.8.... | 0412106v1 |
2001-02-09 | Electron g-factor Engineering in III-V Semiconductors for Quantum Communications | An entanglement-preserving photo-detector converts photon polarization to
electron spin. Up and down spin must respond equally to oppositely polarized
photons, creating a requirement for degenerate spin energies, ge=0 for
electrons. We present a plot of ge-factor versus lattice constant, analogous to
bandgap versus lat... | 0102056v2 |
2007-04-02 | Potfit: effective potentials from ab-initio data | We present a program called potfit which generates an effective atomic
interaction potential by matching it to a set of reference data computed in
first-principles calculations. It thus allows to perform large-scale atomistic
simulations of materials with physically justified potentials. We describe the
fundamental pri... | 0704.0185v2 |
2007-04-07 | Recurrence analysis of the Portevin-Le Chatelier effect | Tensile tests were carried out by deforming polycrystalline samples of
Al-2.5%Mg alloy at room temperature in a wide range of strain rates where the
Portevin-Le Chatelier (PLC) effect was observed. The experimental stress-time
series data have been analyzed using the recurrence analysis technique based on
the Recurrenc... | 0704.0975v1 |
2007-08-10 | Production and application of metal-based nanoparticles | A number of metal-based nanopowders such kinds as Fe, Co, Fe/Co alloy, Fe/C,
Fe/organic shell were successfully produced by aerosol synthesis method. The
mechanism of nanoparticles formation and the influence of experimental
parameters on shape, size distribution, structure, chemical and phase
composition of oxide-, ca... | 0708.1461v1 |
2007-09-16 | Reentrant temperature dependence of critical current in superconductor - ferromagnet - superconductor junctions based on PdFe alloys | The magnetic and transport properties of $Pd_{0.99}Fe_{0.01}$ thin films have
been studied. We have found that the Curie temperature of the films is about 20
K and the magnetic properties strongly depend on temperature below $T_{Curie}$.
We have also fabricated the set of superconductor-ferromagnet-superconductor
josep... | 0709.2495v1 |
2007-09-27 | Aging, Fragility and Reversibility Window in Bulk Alloy Glasses | Non-reversing relaxation enthalpies (DHnr) at glass transitions Tg(x) in the
PxGexSe1-2x ternary display wide, sharp and deep global minima (~ 0) in the
0.09 < x < 0.145 range, within which Tgs become thermally reversing. In this
reversibility window, glasses are found not to age, in contrast to aging
observed for frag... | 0709.4442v1 |
2007-11-05 | Hysteretic magnetotransport in p-type AlGaAs heterostructures with In/Zn/Au ohmic contacts | The two-terminal magneto-conductance of a hole gas in C-doped AlGaAs/GaAs
heterostructures with ohmic contacts consisting of alloyed In/Zn/Au displays a
pronounced hysteresis of the conductance around zero magnetic field. The
hysteresis disappears above magnetic fields of around 0.5 T and temperatures
above 300 mK. For... | 0711.0534v1 |
2007-11-26 | A simple and efficient model for mesoscale solidification simulation of globular grain structures | A simple model for the solidification of globular grains in metallic alloys
is presented. Based on the Voronoi diagram of the nuclei centers, it accounts
for the curvature of the grains near triple junctions. The predictions of this
model are close to those of more refined approaches such as the phase field
method, but... | 0711.4122v1 |
2008-02-05 | Electronic structure of noble metal impurities in semiconductors: Cu in GaP | A numerical method for calculation of the electronic structure of transition
metal impurities in semiconductors based on the Green function technique is
developed. The electronic structure of 3d impurity is calculated within the
LDA+U version of density functional method, whereas the host electron Green
function is cal... | 0802.0605v1 |
2008-02-14 | Elastocaloric effect associated with the martensitic transition in shape-memory alloys | The elastocaloric effect in the vicinity of the martensitic transition of a
Cu-Zn-Al has been studied by inducing the transition by strain or stress
measurements. While transition trajectories show significant differences, the
entropy change associated with the whole transformation (\DeltaSt) is
coincident in both kind... | 0802.2009v1 |
2008-02-20 | Markov Property of Continuous Dislocation Band Propagation | Tensile tests were carried out by deforming polycrystalline samples of
substitutional Al-2.5%Mg alloy at room temperature for a range of strain rates.
The Portevin-Le Chatelier (PLC) effect was observed throughout the strain rate
regime. The deformation bands in this region are found to be of type A in
nature. From the... | 0802.2754v2 |
2008-02-25 | Electronic structure and ferromagnetic behavior in the $Mn_{1-x}A_xAs_{1-y}B_y$ alloys | In this work, a systematic ab initio study of the influence of doping on
electronic structure and local magnetic moments of ferromagnetic MnAs has been
carried out. The majority of the considered substitution elements, potentially
suitable for modification of MnAs as working material of magnetic refrigerators
is shown ... | 0802.3686v1 |
2008-04-01 | Composition and field tuned magnetism and superconductivity in Nd1-xCexCoIn5 | The Nd1-xCexCoIn5 alloys evolve from local moment magnetism (x = 0) to heavy
fermion superconductivity (x =1). Magnetic order is observed over a broad range
of x. For a substantial range of x (0.83 <= x <= 0.95) in the temperature -
composition phase diagram we find that superconductivity may coexist with spin
- densit... | 0804.0225v1 |
2008-04-10 | Structural Ordering and Antisite Defect Formation in Double Perovskites | We formulate an effective model for B-B' site ordering in double perovskite
materials A_2BB'O_6. Even within the simple framework of lattice-gas type
models, we are able to address several experimentally observed issues including
nonmonotonic dependence of the degree of order on annealing temperature, and
the rapid dec... | 0804.1681v1 |
2008-04-16 | On the solubility of Nd3+ in Y3Al5O12 | Neodymium doped yttrium aluminum garnet powders (Nd:YAG or
(Y{1-x}Nd{x})3Al5O12, x=0.15, 0.25, or 0.30, respectively) were prepared by a
sol-gel technique. By DTA measurements up to 2000 deg C eutectic and liquidus
temperatures could be determined. Exothermal peaks in the second and subsequent
DTA heating runs indicate... | 0804.2545v1 |
2008-05-16 | Frustration of tilts and A-site driven ferroelectricity in KNbO_3-LiNbO_3 alloys | Density functional calculations for K_{0.5}Li_{0.5}NbO_3 show strong A-site
driven ferroelectricity, even though the average tolerance factor is
significantly smaller than unity and there is no stereochemically active A-site
ion. This is due to the frustration of tilt instabilities by A-site disorder.
There are very la... | 0805.2475v1 |
2008-06-10 | Geometrical control of the magnetization direction in high aspect-ratio PdNi ferromagnetic nano-electrodes | We present a study of electron-beam evaporated Pd0.4Ni0.6 alloy thin films by
means of ferromagnetic resonance measurements on extended films of varying
thickness and anisotropic magnetoresistance measurements of lithographically
patterned high aspect-ratio ferromagnetic electrodes, respectively. The results
reveal tha... | 0806.1744v1 |
2008-08-07 | Tetragonal to orthorhombic phase transition in SmFeAsO: a synchrotron powder diffraction investigation | The crystal structure of SmFeAsO has been investigated by means of Rietveld
refinement of high resolution synchrotron powder diffraction data collected at
300 K and 100 K. The compound crystallizes in the tetragonal P4/nmm space group
at 300 K and in the orthorhombic Cmma space group at 100 K; attempts to refine
the lo... | 0808.1024v1 |
2008-09-09 | A genetic algorithm for the atomistic design and global optimisation of substitutionally disordered materials | We present a genetic algorithm for the atomistic design and global
optimisation of substitutionally disordered bulk materials and surfaces.
Premature convergence which hamper conventional genetic algorithms due to
problems with synchronisation is avoided using a symmetry adapted crossover.
The algorithm outperforms pre... | 0809.1613v1 |
2008-09-11 | Hexagonal eutectic solidification patterns operating near a marginal stability point | We study the long-time dynamics of hexagonal directional-solidification
patterns in bulk samples of a transparent eutectic alloy using an optical
method which permits real-time observation of the growth front. A slow
dilatation of the patterns due to a slight curvature of the isotherms drives
the system into a permanen... | 0809.1920v1 |
2008-09-16 | Effect of the Dielectric-Constant Mismatch and Magnetic Field on the Binding Energy of Hydrogenic Impurities in a Spherical Quantum Dot | Within the effective mass approximation and variational method the effect of
dielectric constant mismatch between the size-quantized semiconductor sphere,
coating and surrounding environment on impurity binding energy in both the
absence and presence of a magnetic field is considered. The dependences of the
binding ene... | 0809.2662v1 |
2008-09-26 | {Spin polarization tuning in Mn$_{x}$Fe$_{1-x}$Ge$_{3}$ | Experimentally, the intermetallic compound Mn$_{4}$FeGe$_{3}$ has been
recently shown to exhibit enhanced magnetic properties and spin polarization
compared to the Mn$_{5}$Ge$_{3}$ parent compound. The present {\em ab-initio}
study focusses on the effect of Fe substitution on the electronic and magnetic
properties of t... | 0809.4680v1 |
2008-10-22 | Determination and prediction of the fretting crack initiation: introduction of the (P,Q,N) representation and definition of a variable process volume | In this work, the crack nucleation under fretting loading is investigated
experimentally with a damage tolerant 2024 aluminium alloy. A new method is
introduced to determine its condition with respect to all loading parameters
including the number of fretting cycles. Further work deals with the prediction
of this thres... | 0810.4096v1 |
2009-03-03 | Localization via fractional moments for models on $\mathbb{Z}$ with single-site potentials of finite support | One of the fundamental results in the theory of localization for discrete
Schr\"odinger operators with random potentials is the exponential decay of
Green's function and the absence of continuous spectrum. In this paper we
provide a new variant of these results for one-dimensional alloy-type
potentials with finitely su... | 0903.0492v3 |
2009-03-05 | Microscopic Aspects of Stretched Exponential Relaxation (SER) | The Scher-Lax-Phillips (SLP) universal minimalist model quantitatively
explains stretching fractions beta(Tg) for a wide variety of relaxation
experiments (nearly 50 altogether) on electronic and molecular glasses and
deeply supercooled liquids by assuming that quasi-particle excitations indexed
by Breit-Wigner channel... | 0903.1067v1 |
2009-03-10 | Destabilization of the Mg-H system through elastic constraints | We tune the thermodynamics of hydrogen absorption in Mg by means of elastic
clamping. The loading isotherms measured by hydrogenography show that Mg films
covered with Mg-alloy-forming elements, such as Pd and Ni, have hydrogen
plateau pressures more than two orders of magnitude higher than bulk Mg at the
same temperat... | 0903.1709v1 |
2009-03-25 | Universal Non-Landau, Self-Organized, Lattice Disordering Percolative Dopant Network Sub-Tc Phase Transitions in Ceramic Superconductors | Ceramic superconductors (cuprates, pnictides, ...) exhibit universal features
in both Tcmax and in their planar lattice disordering measured by EXAFS, as
reflected by three phase transitions. The two highest temperature transitions
are known to be associated with formation of pseudogaps and superconductive
gaps, with c... | 0903.4376v1 |
2009-03-31 | Magnetization driven metal - insulator transition in strongly disordered Ge:Mn magnetic semiconductors | We report on the temperature and field driven metal-insulator transition in
disordered Ge:Mn magnetic semiconductors accompanied by magnetic ordering,
magnetoresistance reaching thousands of percents and suppression of the
extraordinary Hall effect by a magnetic field. Magnetoresistance isotherms are
shown to obey a un... | 0903.5423v1 |
2009-05-02 | Voltage-assisted Magnetization Switching in Ultrathin Fe80Co20 Alloy Layers | Growing demands for the voltage-driven spintronic applications with
ultralow-power consumption have led to new interest in exploring the
voltage-induced magnetization switching in ferromagnetic metals. In this study,
we observed a large perpendicular magnetic anisotropy change in Au(001) /
ultrathin Fe80Co20(001) / MgO... | 0905.0185v1 |
2009-05-05 | A new material for hydrogen storage, ScAl0.8Mg0.2 | A novel aluminium rich alloy for hydrogen storage has been discovered,
ScAl0.8Mg0.2, which has superior properties regarding hydrogen storage
capacity, kinetics and stability towards air oxidation in comparison to
hydrogen absorption in state-of-the-art intermetallic compounds. Detailed
analysis of the hydrogen absorpt... | 0905.0630v2 |
2009-06-22 | Kondo resonance narrowing in d- and f-electron systems | By developing a simple scaling theory for the effect of Hund's interactions
on the Kondo effect, we show how an exponential narrowing of the Kondo
resonance develops in magnetic ions with large Hund's interaction. Our theory
predicts an exponential reduction of the Kondo temperature with spin S of the
Hund's coupled mo... | 0906.4107v1 |
2009-06-29 | Influence of Demagnetization Effect on Giant Magneto Impedance of soft Ferromagnetic Metal | The large change in electromagnetic impedance in ferromagnetic state of soft
magnetic metals in presence of biasing magnetic field is associated with change
in screening of electromagnetic field. The screening depends on the
permeability of the metal. Apart from dependence on intrinsic properties of
metal the permeabil... | 0906.5203v1 |
2009-08-04 | Intersubband carrier scattering in n- and p-Si/SiGe quantum wells with diffuse interfaces | Scattering rate calculations in two-dimensional Si/SiGe systems have
typically been restricted to rectangular Ge profiles at interfaces between
layers. Real interfaces, however, may exhibit diffuse Ge profiles either by
design or as a limitation of the growth process. It is shown here that alloy
disorder scattering dra... | 0908.0552v1 |
2009-09-18 | Electronic transport properties of ternary Cd1-xZnxS nanowire network | We present electronic transport characteristics of ternary alloy Cd1-xZnxS
nanowire networks in the dark and under white light illumination. Compared to
the negligible dark current, we observed a photocurrent enhancement up to 4
orders of magnitude at intensity of 460 mW/cm2. The time constant of the
dynamic photorespo... | 0909.3480v1 |
2009-09-28 | A force torsor analysis for a turning process in the presence of self-excited vibrations | A testing device in turning including, in particular, a six-component
dynamometer, is used to measure the complete torque of the cutting actions, in
a case of self-excited vibrations. For the tests, the used tool was a noncoated
carbide tool (TNMA 160412) without chip breaker. The cutting material is a
chrome molybdenu... | 0909.5015v1 |
2009-10-05 | Amplitude expansion of the binary phase field crystal model | Amplitude representations of a binary phase field crystal model are developed
for a two dimensional triangular lattice and three dimensional BCC and FCC
crystal structures. The relationship between these amplitude equations and the
standard phase field models for binary alloy solidification with elasticity are
derived,... | 0910.0714v1 |
2009-10-06 | Identifying structural order in Selenium with Near-Edge Spectroscopy | We investigate the crystallization of amorphous arsenic-selenium alloys with
0%, 0.5%, 2%, 6%, 10%, and 19% arsenic by atomic concentration using
synchrotron X-ray absorption spectroscopy. We identify crystalline order using
the extended X-ray absorption fine structure (EXAFS) spectra and correlate this
order to change... | 0910.1051v1 |
2009-10-08 | Effective dimensionality of the Portevin - Le Chatelier effect | Tensile tests have been carried out by deforming polycrystalline samples of
substitutional Al-2.5%Mg alloy at room temperature at a range of strain rates.
The Portevin - Le Chatelier (PLC) effect was observed. From an analysis of the
experimental stress versus time series data we have inferred that the dynamics
of the ... | 0910.1450v1 |
2009-10-19 | Evidence for a charge Kondo effect in Pb(1-x)Tl(x)Te from measurements of thermoelectric power | We report measurements of the thermoelectric power (TEP) for a series of
Pb(1-x)Tl(x)Te crystals with x = 0.0 to 1.3%. Although the TEP is very large
for x = 0.0, using a single band analysis based on older work for dilute
magnetic alloys we do find evidence for a Kondo contribution of 11 - 18 uV/K.
This analysis sugge... | 0910.3491v1 |
2009-11-04 | Mott-Hubbard and Anderson metal-insulator transitions in correlated lattice fermions with binary disorder | Strongly correlated fermions in a crystal or in an optical lattice in the
presence of binary alloy disorder are investigated. We employ the statistical
dynamical mean-field theory, which incorporates both, local fluctuations due to
disorder and local correlations due to interaction, to solve the
Anderson-Hubbard model.... | 0911.0934v2 |
2009-11-13 | Calculating the optimum pressure and temperature for vacancy minimization from theory; Niobium is an example | Self-resonance in the atomic vibration occurs when the average wavelength of
the phonon thermal vibration is equivalent or harmonic of the diameters of the
atoms. It is suggested that applying pressure at temperature corresponding to
the self-resonance should effectively reduce the number of vacancies. This
theoretical... | 0911.2728v1 |
2010-01-19 | Glassy Freezing and Long-Range Order in the 3D Random Field $XY$ Model | Monte Carlo studies of the 3D random field $XY$ model on simple cubic
lattices of size $64^3$, using two different isotropic random-field probability
distributions of moderate strength, show a glassy freezing behavior above
$T_c$, and long-range order below $T_c$, consistent with our earlier results
for weaker and stro... | 1001.3397v1 |
2010-01-30 | Thermoelectrically Controlled Spin-Switch | The search for novel spintronic devices brings about new ways to control
switching in magnetic thin-films. In this work we experimentally demonstrate a
device based on thermoelectrically controlled exchange coupling. The read out
signal from a giant magnetoresistance element is controlled by exchange
coupling through a... | 1002.0089v1 |
2010-03-26 | Structurally driven metamagnetism in MnP and related Pnma compounds | We investigate the structural conditions for metamagnetism in MnP and related
materials using Density Functional Theory. A magnetic stability plot is
constructed taking into account the two shortest Mn-Mn distances. We find that
a particular Mn-Mn separation plays the dominant role in determining the change
from antife... | 1003.5193v2 |
2010-03-28 | Black Hole Thermodynamics and Heavy Fermion Metals | Heavy fermion alloys at critical doping typically exhibit non-Fermi-liquid
behavior at low temperatures, including a logarithmic or power law rise in the
ratio of specific heat to temperature as the temperature is lowered. Anomalous
specific heat of this type is also observed in a simple class of gravitational
dual mod... | 1003.5361v3 |
2010-04-06 | The CNT/BCN/CNT structure (zigzag type) as a molecular switch | Using a tight-binding model and some well-known approaches and methods based
on Green's function theory and Landauer formalism, we numerically investigate
the conductance properties and I-V characteristics of zigzag single-walled BCN
alloy nanotube in the CNT/BCN/CNT structure, where nanocontacts are considered
as zigz... | 1004.0827v1 |
2010-04-14 | Theory of the ferromagnetism in TiCrN solid solutions | First-principles calculations are used to investigate the magnetic properties
of Ti$_{1-x}$Cr$_{x}$N solid solutions. We show that the magnetic interactions
between Cr spins that favour antiferromagnetism in CrN is changed upon alloying
with TiN leading to the appearance of ferromagnetism in the system at
approximately... | 1004.2337v1 |
2010-04-26 | Electrical conductivity in graphene with point defects | The electrical conductivity of graphene containing point defects is studied
within the binary alloy model in its dependence on the Fermi level position at
the zero temperature. It is found that the minimal conductivity value does not
have a universal character and corresponds to the impurity resonance energy
rather tha... | 1004.4606v2 |
2010-05-04 | Moessbauer and magnetic measurements of superconducting LiFeP | The LiFeP sample has been prepared by means of high-temperature solid state
reaction. A transition temperature to the superconducting state was found as
about 5.5 K by measurements of magnetization versus temperature. The second
critical field was found above 1 kOe. Moessbauer spectra of the LiFeP phase are
characteriz... | 1005.0494v2 |
2010-05-21 | A model of homogeneous semicoherent interphase boundary for heterophase precipitates in substitution alloys under irradiation | The model of homogeneous semicoherent interphase boundary describes the
processes of absorption and thermoactivated migration of irradiation-produced
inequilibrium point defects at a semicoherent boundary between a heterophase
precipitate and a substitution solid solution. Within this model the kinetics
of evolution of... | 1005.3995v1 |
2010-05-30 | Defects and multistability in eutectic solidification patterns | We use three-dimensional phase-field simulations to investigate the dynamics
of the two-phase composite patterns formed upon during solidification of
eutectic alloys. Besides the spatially periodic lamellar and rod patterns that
have been widely studied, we find that there is a large number of additional
steady-state p... | 1005.5566v1 |
2010-08-23 | Field induced changes across magnetic compensation in Pr(1-x)Gd(x)Al(2) alloys | The magnetic compensation phenomenon has been explored in the
Pr(1-x)Gd(x)Al(2) series. The contributions from Pr and Gd moments compensate
each other at a specific temperature in the ordered state (below (T(c)). At
high fields, the magnetic reorientation (with respect to the external field
direction) of the Pr and Gd ... | 1008.3782v1 |
2010-10-11 | Spin-orbit fields in asymmetric (001) quantum wells | We measure simultaneously the in-plane electron g-factor and spin relaxation
rate in a series of undoped inversion-asymmetric (001)-oriented GaAs/AlGaAs
quantum wells by spin-quantum beat spectroscopy. In combination the two
quantities reveal the absolute values of both the Rashba and the Dresselhaus
coefficients and p... | 1010.2142v1 |
2010-10-19 | Self-organized criticality as a precursor of fatigue: application to shape memory alloys | Fatigue failure can be thought by studying the collective motions of defects
inside materials instead of focusing on the growth of a pre-existing
micro-crack. An experimental study of the statistical distribution of acoustic
emissions avalanches along cycling is presented. The evolutions of critical
exponents through c... | 1010.3828v2 |
2010-11-16 | Negative refraction in natural ferromagnetic metals | It is generally believed that Veselago's criterion for negative refraction
cannot be fulfilled in natural materials. However, considering imaginary parts
of the permittivity ({\epsilon}) and permeability ({\mu}) and for metals at not
too high frequencies the general condition for negative refraction becomes
extremely s... | 1011.3663v1 |
2011-01-11 | Designed Metamagnetism in CoMnGe_{1-x}P_{x} | We extend our previous theoretical study of Mn-based orthorhombic metamagnets
to those that possess large nearest neighbour Mn-Mn separations (d1>3.22A).
Based on our calculations, we design and synthesize a series of alloys,
CoMnGe_{1-x}P_{x}, to experimentally demonstrate the validity of the model.
Unusually, we pred... | 1101.2099v1 |
2011-01-21 | Cr doped III-V nitrides: potential candidates for spintronics | Studies of Cr-doped III-V nitrides, dilute magnetic alloys, in the
zinc-blende crystal structure are presented. The objective of the work is to
investigate half-metallicity in Al(0.75)Cr(0.25)N, Ga(0.75)Cr(0.25)N and
In(0.75)Cr(0.25)N for their possible application in the spin based electronic
devices. The calculated s... | 1101.4059v1 |
2011-01-25 | Large exchange bias after zero-field cooling from an unmagnetized state | Exchange bias (EB) is usually observed in systems with interface between
different magnetic phases after field cooling. Here we report an unusual
phenomenon in which a large EB can be observed in Ni-Mn-In bulk alloys after
zero-field cooling from an unmagnetized state. We propose this is related to
the newly formed int... | 1101.4737v1 |
2011-02-05 | Simulations of decomposition kinetics of Fe-Cr solid solutions during thermal aging | The decomposition of Fe-Cr solid solutions during thermal aging is modeled by
Atomistic Kinetic Monte Carlo (AKMC) simulations, using a rigid lattice
approximation with composition dependant pair interactions that can reproduce
the change of sign of the mixing energy with the alloy composition. The
interactions are fit... | 1102.1091v1 |
2011-02-25 | First-principles calculations of magnetization relaxation in pure Fe, Co, and Ni with frozen thermal lattice disorder | The effect of the electron-phonon interaction on magnetization relaxation is
studied within the framework of first-principles scattering theory for Fe, Co,
and Ni by displacing atoms in the scattering region randomly with a thermal
distribution. This "frozen thermal lattice disorder" approach reproduces the
non-monoton... | 1102.5305v2 |
2011-04-08 | Materials and mechanisms of hole superconductivity | The theory of hole superconductivity proposes that there is a single
mechanism of superconductivity that applies to all superconducting materials.
This paper discusses several material families where superconductivity occurs
and how they can be understood within this theory. Materials discussed include
the elements, tr... | 1104.1624v2 |
2011-04-28 | Global existence result for phase transformations with heat transfer in shape memory alloys | We consider three-dimensional models for rate-independent processes
describing materials undergoing phase transformations with heat transfer. The
problem is formulated within the framework of generalized standard solids by
the coupling of the momentum equilibrium equation and the flow rule with the
heat transfer equati... | 1104.5408v1 |
2011-05-03 | An Improved CVM Entropy Functional for BCC Alloys | We explore the possibility of modifying the multiplicity of the basic cluster
in the entropy functional used in the cluster variation method so that
truncation errors owing to finite size of the basic cluster may be corrected.
The numerical value of this multiplicity is found by requiring the modified CVM
entropy funct... | 1105.0536v1 |
2011-08-10 | A route towards finding large magnetic anisotropy in nano-composites: application to a W$_{1-x}$Re$_x$/Fe multilayer | We suggest here a novel nano-laminate, 5[Fe]/2[W$_x$Re$_{1-x}$] (x=0.6-0.8),
with enhanced magnetic hardness in combination with a large saturation moment.
The calculated magnetic anisotropy of this material reaches values of 5.3-7.0
MJ/m$^3$, depending on alloying conditions. We also propose a recipe in how to
identif... | 1108.2105v1 |
2011-11-30 | Ab-initio modeling of the short range order in Fe-N and Fe-C austenitic alloys | In the present paper, we have studied atomic structure of nitrogenous
austenite. High precision ab-initio calculation was utilized for the
calculation of the pair potentials of interatomic interactions N-N in FCC Fe
lattice. These potentials were used for the Monte Carlo modeling of the short
range order in the Fe-N sy... | 1111.7203v1 |
2011-12-15 | Diffusion-Induced Oscillations of Extended Defects | From a simple model for the driven motion of a planar interface under the
influence of a diffusion field we derive a damped nonlinear oscillator equation
for the interface position. Inside an unstable regime, where the damping term
is negative, we find limit-cycle solutions, describing an oscillatory
propagation of the... | 1112.3669v1 |
2011-12-17 | Capillary-Wave Description of Rapid Directional Solidification | A recently introduced capillary-wave description of binary-alloy
solidification is generalized to include the procedure of directional
solidification. For a class of model systems a universal dispersion relation of
the unstable eigenmodes of a planar steady-state solidification front is
derived, which readjusts previou... | 1112.4091v1 |
2012-01-31 | Exchange-induced phase separation in Ni-Cu films | Magneto-structural properties of films of diluted ferromagnetic alloys
Ni$_x$Cu$_{1-x}$ in the concentration range $0.7 < x < 1.0$ are studied
experimentally. Films deposited by magnetron sputtering show partial phase
separation, as evidenced by structural analysis and ferromagnetic resonance
measurements. The phase di... | 1201.6493v1 |
2012-02-06 | Magnetostructural study of the (Mn,Fe)3(P,Si) system | Using X-ray diffraction, DSC and magnetization measurements, a
magnoestructural map of the (Mn,Fe)3(Si,P) system was assembled and reported in
the current paper. Besides the already known cubic phase for Mn3-xFexSi system
and the tetragonal and orthorhombic phases for the Mn3-xFexP system, a novel
hexagonal phase has b... | 1202.1173v1 |
2012-03-03 | Scaling of intrinsic Gilbert damping with spin-orbital coupling strength | We have experimentally and theoretically investigated the dependence of the
intrinsic Gilbert damping parameter $\alpha_0$ on the spin-orbital coupling
strength $\xi$ by using L1$_{\mathrm{0}}$ ordered
FePd$_{\mathrm{1-x}}$Pt$_{\mathrm{x}}$ ternary alloy films with perpendicular
magnetic anisotropy. With the time-resol... | 1203.0607v1 |
2012-03-26 | Electrochemical integration of graphene with light absorbing copper-based thin films | We present an electrochemical route for the integration of graphene with
light sensitive copper-based alloys used in optoelectronic applications.
Graphene grown using chemical vapor deposition (CVD) transferred to glass is
found to be a robust substrate on which photoconductive Cu_{x}S films of 1-2 um
thickness can be ... | 1203.5655v1 |
2012-03-27 | Symmetries of 2-lattices and second order accuracy of the Cauchy--Born Model | We show that the Cauchy--Born model of a single-species 2-lattice is second
order if the atomistic and continuum kinematics are connected in a novel way.
Our proof uses a generalization to 2-lattices of the point symmetry of Bravais
lattices. Moreover, by identifying similar symmetries in multi-species pair
interaction... | 1203.5854v1 |
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