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2024-02-10
A space-time gauge theory for modeling ductile damage and its NOSB peridynamic implementation
Local translational and scaling symmetries in space-time is exploited for modelling ductile damage in metals and alloys over wide ranges of strain rate and temperature. The invariant energy density corresponding to the ductile deformation is constructed through the gauge invariant curvature tensor by imposing the Weyl ...
2403.09685v1
2024-03-14
Adapting OC20-trained EquiformerV2 Models for High-Entropy Materials
Computational high-throughput studies, especially in research on high-entropy materials and catalysts, are hampered by high-dimensional composition spaces and myriad structural microstates. They present bottlenecks to the conventional use of density functional theory calculations, and consequently, the use of machine-l...
2403.09811v1
2024-03-18
Laser Annealed Two Dimensional SiO2/Si1-xGex Scaffolds for Nanoscaled Devices, Synergy of Experiment and Computation
Ultraviolet nanosecond laser annealing (UV-NLA) proves to be an important technique, particularly when tightly controlled heating and melting are necessary. In the realm of semiconductor technologies, the significance of laser annealing (NLA) grows in tandem with the escalating intricacy of integration schemes in nano-...
2403.11606v1
2024-03-19
Nanoscale brittle-to-ductile transition of the C15 CaAl$_2$ Laves phase
The influence of temperature on the deformation behaviour of the C15 CaAl$_2$ Laves phase, a key constituent for enhancing the mechanical properties of Mg alloys up to service temperatures of 200 {\deg}C, remains largely unexplored. This study presents, for the first time, the nanoscale brittle-to-ductile transition (B...
2403.12507v1
2024-03-28
MaterialsMap: A CALPHAD-Based Tool to Design Composition Pathways through feasibility map for Desired Dissimilar Materials, demonstrated with RSW Joining of Ag-Al-Cu
Assembly of dissimilar metals can be achieved by different methods, for example, casting, welding, and additive manufacturing (AM). However, undesired phases formed in liquid-phase assembling processes due to solute segregation during solidification diminish mechanical and other properties of the processed parts. In th...
2403.19084v1
2024-04-01
Stabilization and high thermoelectric performance of high-entropy-type cubic AgBi(S, Se, Te)2
As thermoelectric generators can convert waste heat into electricity, they play an important role in energy harvesting. The metal chalcogenide AgBiSe2 is one of the high-performance thermoelectric materials with low lattice thermal conductivity (klat), but it exhibits temperature-dependent crystal structural transition...
2404.00984v1
2024-04-01
MICROSIM: A high performance phase-field solver based on CPU and GPU implementations
The phase-field method has become a useful tool for the simulation of classical metallurgical phase transformations as well as other phenomena related to materials science. The thermodynamic consistency that forms the basis of these formulations lends to its strong predictive capabilities and utility. However, a strong...
2404.01035v1
2024-04-03
Tuning superconductivity in nanosecond laser annealed boron doped $Si_{1-x}Ge_{x}$ epilayers
Superconductivity in ultra-doped $Si_{1-x}Ge_{x}:B$ epilayers is demonstrated by nanosecond laser doping, which allows introducing substitutional B concentrations well above the solubility limit and up to $7\,at.\%$. A Ge fraction $x$ ranging from 0 to 0.21 is incorporated in $Si:B$ : 1) through a precursor gas by Gas ...
2404.02748v1
2024-04-07
Element-specific ultrafast lattice dynamics in FePt nanoparticles
Light-matter interaction at the nanoscale in magnetic alloys and heterostructures is a topic of intense research in view of potential applications in high-density magnetic recording. While the element-specific dynamics of electron spins is directly accessible to resonant x-ray pulses with femtosecond time structure, th...
2404.04980v2
2024-04-10
Origin of pinning disorder in magnetic-field-induced Wigner solids
At low Landau level filling factors ($\nu$), Wigner solid phases of two-dimensional electron systems in GaAs are pinned by disorder, and exhibit a pinning mode, whose frequency is a measure of the disorder that pins the Wigner solid. Despite numerous studies spanning the last three decades, the origin of the disorder t...
2404.07369v1
2024-04-11
Wettability-dependent dissolution dynamics of oxygen bubbles on Ti64 substrates
In this study, the dissolution of a single oxygen bubble on a solid surface, here Titianium alloy Ti64, in ultrapure water with different oxygen undersaturation levels is investigated. For that purpose, a combination of shadowgraph technique and planar laser-induced fluorescence is used to measure simultaneously the ch...
2404.07483v1
2024-03-14
Analysis of growth of silicon thin films on textured and non-textured surface
Hydrogenated amorphous silicon alloy films are generally deposited by radio frequency plasma enhanced chemical vapor deposition (RF PECVD) technique on various types of substrates. Generally it is assumed that film quality remains unchanged when deposited on textured or non-textured substrates. Here we analyzed the dif...
2404.08651v1
2024-04-13
Layer-by-layer connection for large area single crystal boron nitride multilayer films
Boron nitride (BN) is today considered as one of the most promising materials for many novel applications including bright single photon emission, deep UV opto-electronics, small sized solid-state neutron detector, and high-performance two-dimensional materials, etc. Despite the recent successful fabrication of large-a...
2404.08875v1
2024-04-17
Interplay between magnetic and lattice excitations and emergent multiple phase transitions in MnPSe3-xSx
The intricate interplay between spin and lattice degrees of freedom in two-dimensional magnetic materials plays a pivotal role in modifying their magnetic characteristics, engendering hybrid quasiparticles, and implementing functional devices. Herein, we present our comprehensive and in-depth investigations on magnetic...
2404.11099v1
2006-06-25
Uranium partitioning between liquid iron and silicate melt at high pressures: implications for uranium solubility in planetary cores
We have investigated the partitioning of U between silicate melt and Fe liquid at pressures of 3.0 to14.5 GPa and temperatures of 1660 to 2500 oC. The solubility of U in liquid Fe is in the range of 0.6 to 800 ppm and increases with temperature (T) and pressure (P). When P = or > 7 GPa and T > Tmelt of the silicate pha...
0606614v4
1998-01-09
Band-width control in a perovskite-type 3d^1 correlated metal Ca_{1-x}Sr_xVO_3. I. Evolution of the electronic properties and effective mass
Single crystals of the perovskite-type $3d^{1}$ metallic alloy system Ca$_{1-x}$Sr$_x$VO$_3$ were synthesized in order to investigate metallic properties near the Mott transition. The substitution of a Ca$^{2+}$ ion for a Sr$^{2+}$ ion reduces the band width $W$ due to a buckling of the V-O-V bond angle from $\sim180^\...
9801073v3
1999-01-13
Influence of uniaxial stress on the lamellar spacing of eutectics
Directional solidification of lamellar eutectic structures submitted to uniaxial stress is investigated. In the spirit of an approximation first used by Jackson and Hunt, we calculate the stress tensor for a two-dimensional crystal with triangular surface, using a Fourier expansion of the Airy function. crystal with tr...
9901120v1
2000-02-25
Phonon Scattering and Internal Friction in Dielectric and Metallic Films at Low Temperatures
We have measured the heat conduction between 0.05 K and 1.0 K of high purity silicon wafers carrying on their polished faces a variety of thin dielectric films and polycrystalline thin metallic films. Using a Monte Carlo simulation to analyze the conduction measurements, we have determined the phonon mean free path wit...
0002413v2
2001-03-20
Thin Film Magnesium Boride Superconductor with Very High Critical Current Density and Enhanced Irreversibility Field
The discovery of superconductivity at 39 K in magnesium diboride offers the possibility of a new class of low-cost, high-performance superconducting materials for magnets and electronic applications. With twice the critical temperature of Nb_3Sn and four times that of Nb-Ti alloy, MgB_2 has the potential to reach much ...
0103425v1
2002-03-15
Distribution of carbon atoms in iron-carbon fcc phase: an experimental and theoretical study
This paper presents an experimental and theoretical study of the distribution of carbon atoms in the octahedral interstitial sites of the face-centered cubic (fcc) phase of the iron-carbon system. The experimental part of the work consists of Mossbauer measurements in Fe-C alloys with up to about 12 atomic percent C, w...
0203327v1
2004-11-17
Electronic structure and magnetic properties of RMnX (R= Mg, Ca, Sr, Ba, Y; X= Si, Ge) studied by KKR method
Electronic structure calculations, using the charge and spin self-consistent Korringa- Kohn-Rostoker (KKR) method, have been performed for several $R$Mn$X$ compounds ($R$ = Mg, Ca, Sr, Ba, Y; $X$ = Si, Ge) of the CeFeSi-type structure. The origin of their magnetic properties has been investigated emphasizing the role o...
0411436v1
2005-06-28
Excitons, biexcitons and trions in self-assembled (In,Ga)As/GaAs quantum dots: Recombination energies, polarization and radiative lifetimes versus dot height
We calculate the height dependence of recombination energies, polarization and radiative lifetimes of the optical transitions of various excitonic complexes: neutral excitons (X^0), negatively- (X^-) and positively-charged (X^+) trions, and biexcitons (XX^0) in lens-shaped, self-assembled In_0.6Ga_0.4As/GaAs quantum do...
0506714v2
2008-01-31
Zero-field spin-splitting and spin lifetime in n-InSb/In1-xAlxSb asymmetric quantum well heterostructures
The spin-orbit (SO) coupling parameters for lowest conduction subband due to structural (SIA) and bulk (BIA) inversion asymmetry are calculated for a range of carrier densities in [001]-grown delta-doped n-type InSb/In1-xAlxSb asymmetric quantum wells using the established 8 band k.p formalism [PRB 59,8 R5312 (1999)]. ...
0801.4849v2
2008-06-09
Detection of high energy cosmic rays with the resonant gravitational wave detector NAUTILUS and EXPLORER
The cryogenic resonant gravitational wave detectors NAUTILUS and EXPLORER, made of an aluminum alloy bar, can detect cosmic ray showers. At temperatures above 1 K, when the material is in the normal conducting state, the measured signals are in good agreement with the values expected based on the cosmic rays data and o...
0806.1335v2
2008-07-17
The sign of electron g-factor in GaAs(1-x)N(x) measured by using the Hanle effect
Positive signs of the effective g-factors for free electrons in the conduction band and electrons localized on deep paramagnetic centers have been measured in nitrogen dilute alloy GaAs{0.979}N{0.021} at room temperature. The g-factor signs have been determined from an asymmetry in the depolarization of edge photolumin...
0807.2842v1
2008-08-04
Local structures of polar wurtzites Zn_{1-x}Mg_{x}O studied by Raman and {67}Zn/{25}Mg NMR spectroscopies and by total neutron scattering
Local compositions and structures of Zn_{1-x}Mg_{x}O alloys have been investigated by Raman and solid-state {67}Zn/{25}Mg nuclear magnetic resonance (NMR) spectroscopies, and by neutron pair-distribution-function (PDF) analyses. The E2(low) and E2(high) Raman modes of Zn_{1-x}Mg_{x}O display Gaussian- and Lorentzian-ty...
0808.0492v1
2009-11-12
Carrier-induced refractive index change and optical absorption in wurtzite InN and GaN: Fullband approach
Based on the full band electronic structure calculations, first we consider the effect of n-type doping on the optical absorption and the refractive index in wurtzite InN and GaN. We identify quite different dielectric response in either case; while InN shows a significant shift in the absorption edge due to n-type dop...
0911.2312v2
2010-12-03
Room temperature ferromagnetism and anomalous Hall effect in Si_{1-x}Mn_x (x = 0.35) alloys
A detailed study of the magnetic and transport properties of Si1-xMnx (X = 0.35) films is presented. We observe the anomalous Hall effect (AHE) in these films up to room temperature. The results of the magnetic measurements and the AHE data are consistent and demonstrate the existence of long-range ferromagnetic (FM) o...
1012.0715v1
2011-07-16
Intrinsic anomalous Hall effect in nickel: An GGA+U study
The electronic structure and intrinsic anomalous Hall conductivity of nickel have been calculated based on the generalized gradient approximation (GGA) plus on-site Coulomb interaction (GGA+U) scheme. It is found that the intrinsic anomalous Hall conductivity ($\sigma_{xy}^H$) obtained from the GGA+U calculations with ...
1107.3242v2
2011-09-09
First-principles Electronic Structure of Superconductor Ca$_4$Al$_2$O$_6$Fe$_2$P$_2$: Comparison with LaFePO and Ca$_4$Al$_2$O$_6$Fe$_2$As$_2$
We investigate the electronic structures of iron-based superconductors having perovskite-like blocking layers, %Ca$_4$Al$_2$O$_6$Fe$_2$(As$_{1-x}$P$_x$)$_2$ from first principles. Ca$_4$Al$_2$O$_6$Fe$_2$P$_2$ and Ca$_4$Al$_2$O$_6$Fe$_2$As$_2$ from first principles. Ca$_4$Al$_2$O$_6$Fe$_2$P$_2$ is found to have two hole...
1109.2054v2
2011-09-10
Structural and Optical properties of Zn(1-x)MgxO nanocrystals obtained by low temperature method
In this paper we report structural and optical properties of Magnesium substituted Zinc Oxide (Zn1-xMgxO) nanocrystals (~10-12nm) synthesized by low temperature route. In the low temperature synthesis route it was possible to reach x = 0.17 without segregation of Mg rich phase. The exact chemical composition has been e...
1109.2250v1
2011-11-21
Densest binary sphere packings
The densest binary sphere packings in the alpha-x plane of small to large sphere radius ratio alpha and small sphere relative concentration x have historically been very difficult to determine. Previous research had led to the prediction that these packings were composed of a few known "alloy" phases including, for exa...
1111.4917v2
2012-05-04
Nonlinear mushy-layer convection with chimneys: stability and optimal solute fluxes
We model buoyancy-driven convection with chimneys -- channels of zero solid fraction -- in a mushy layer formed during directional solidification of a binary alloy in two-dimensions. A large suite of numerical simulations is combined with scaling analysis in order to study the parametric dependence of the flow. Stabili...
1205.0964v2
2012-05-28
Origin of the Heavy Fermion Behavior in Ca_{2-x}Sr_{x}RuO_{4}: Roles of Coulomb Interaction and the Rotation of RuO_{6} octahedra
We study the electronic states for Ca_{2-x}Sr_{x}RuO_{4} in $0.5\leq x \leq 2$ within the Gutzwiller approximation (GA) on the basis of the three-orbital Hubbard model for the Ru t_{2g} orbitals. The main effects of the Ca substitution are taken account as the changes of the $dp$ hybridizations between the Ru 4d and O ...
1205.6053v2
2013-04-23
Thermodynamic and mechanical properties of copper precipitates in alpha-iron from atomistic simulations
The Fe-Cu system has attracted much attention over the last several decades due to its technological importance as a model alloy for Cu steels. In spite of these efforts several aspects of its phase diagram remain unexplained. Here we use atomistic simulations to characterize the polymorphic phase diagram of Cu precipi...
1304.6187v2
2013-05-13
The algebraic cast of Poincaré's Méthodes nouvelles de la mécanique céleste
This paper aims at shedding a new light on the novelty of Poincar\'e's M\'ethodes nouvelles de la m\'ecanique c\'eleste. The latter's approach to the three-body-problem has often been celebrated as a starting point of chaos theory in relation to the investigation of dynamical systems. Yet, the novelty of Poincar\'e's s...
1305.2689v1
2013-05-22
Non-Fermi liquid behaviour from dynamical effects of impurity scattering in correlated Fermi liquids
The interplay of disorder and interactions is a subject of perennial interest. In this work, we have investigated the effect of disorder due to chemical substitution on the dynamics and transport properties of correlated Fermi liquids. A low frequency analysis in the concentrated and dilute limits shows that the dynami...
1305.5111v4
2013-06-06
Hydrostatic strain enhancement in laterally confined SiGe nanostripes
Strain-engineering in SiGe nanostructures is fundamental for the design of optoelectronic devices at the nanoscale. Here we explore a new strategy, where SiGe structures are laterally confined by the Si substrate, to obtain high tensile strain avoiding the use of external stressors, and thus improving the scalability. ...
1306.1412v1
2013-07-16
The influence of Auger recombination on the performance of quantum-dot light-emitting diodes
A growing interest in colloidal quantum dot (QD) based light-emitting diodes (QD-LEDs) has been motivated by the exceptional color purity and spectral tunability of QD emission as well as the amenability of QD materials to highly scalable and inexpensive solution processing. One current challenge in the QD-LED field ha...
1307.4434v2
2013-10-07
Topological phase transitions in (Bi$_{1-x}$In$_{x})_2$Se$_3$ and (Bi$_{1-x}$Sb$_{x})_2$Se$_3$
We study the phase transition from a topological to a normal insulator with concentration $x$ in (Bi$_{1-x}$In$_{x})_2$Se$_3$ and (Bi$_{1-x}$Sb$_{x})_2$Se$_3$ in the Bi$_2$Se$_3$ crystal structure. We carry out first-principles calculations on small supercells, using this information to build Wannierized effective Hami...
1310.1692v2
2013-10-16
Macroscopic Elastic Properties of Textured ZrN--AlN Polycrystalline Aggregates: From Ab initio Calculations to Grain-Scale Interactions
Despite the fast development of computational materials modelling, theoretical description of macroscopic elastic properties of textured polycrystalline aggregates starting from basic principles remains a challenging task. In this communication we use a supercell-based approach to obtain the elastic properties of rando...
1310.4344v2
2013-10-24
Examination of the tradeoff between intrinsic and extrinsic properties in the optimization of a modern internal tin Nb3Sn conductor
In modern Nb3Sn wires there is a fundamental compromise to be made between optimizing the intrinsic properties associated with the superfluid density in the A15 phase (e.g. Tc, Hc, Hc2, all of which are composition dependent), maximizing the quantity of A15 that can be formed from a given mixture of Nb, Sn and Cu, mini...
1310.6729v2
2013-12-08
Atomic-scale analysis of liquid-gallium embrittlement of aluminum grain boundaries
In this work, we explore the role of atomistic-scale energetics on liquid-metal embrittlement of Al due to Ga. Ab initio and molecular mechanics were employed to probe the binding energies of vacancies and segregation energies of Ga for <100>, <110> and <111> STGBs in Al. We found that the GB local arrangements and res...
1312.2160v2
2014-01-29
Seeded growth of monodisperse and spherical silver nanoparticles
Aiming at spherical and monodisperse silver nanoparticles with diameters up to 100 nm, the potential of heterogeneous nucleation of silver particles was explored. Gold seed particles, mainly produced with a spark discharge generator, were carried by nitrogen through a three-zone tube furnace. Silver was evaporated at 1...
1401.7554v3
2014-03-03
Bayesian Density Estimation via Multiple Sequential Inversions of 2-D Images with Application in Electron Microscopy
We present a new Bayesian methodology to learn the unknown material density of a given sample by inverting its two-dimensional images that are taken with a Scanning Electron Microscope. An image results from a sequence of projections of the convolution of the density function with the unknown microscopy correction func...
1403.0510v1
2014-03-18
Exploring high temperature magnetic order in CeTi_1-xSc_xGe
Most of magnetic transitions related to Ce ordering are found below T_ord~12K. Among the few cases exceeding that temperature, two types of behaviors can be distinguished. One of them is related to the rare cases of Ce binary compounds formed in BCC structures, with a quartet ground state, whose degeneracy is reduced b...
1403.4490v1
2014-07-02
Quadrupolar Singlet Ground State of Praseodymium in a Modulated Pyrochlore
The complex structure and magnetism of Pr$_{2-x}$Bi$_x$Ru$_2$O$_7$ was investigated by neutron scattering and EXAFS. Pr has an approximate doublet ground-state and the first excited state is a singlet. This overall crystal field level scheme is similar to metallic Pr$_2$Ir$_2$O$_7$, which is also reported here. While t...
1407.0661v1
2014-07-30
Transition metal solute interactions with point defects in austenitic iron from first principles
We present a comprehensive set of first principles electronic structure calculations to study transition metal solutes and their interactions with point defects in austenite. Clear trends were observed across the series. Solute-defect interactions were strongly correlated to the solute size factors, consistent with loc...
1407.7996v1
2014-12-09
Properties and Collapse of the Ferromagnetism in UCo1-xRuxAl Studied in Single Crystals
We have investigated the ferromagnetic (FM) phase which suddenly develops in UCo1-xRuxAl and is isolated by paramagnetic regions on both sides from the parent UCoAl and URuAl. For that purpose we have grown high quality single crystals with x = 0.62, 0.70, 0.74, 0.75 and 0.78. The properties of the FM phase have been i...
1412.2904v2
2015-02-03
Irreversible transformation of ferromagnetic ordered stripe domains in single-shot IR pump - resonant X-ray scattering probe experiments
The evolution of a magnetic domain structure upon excitation by an intense, femtosecond Infra-Red (IR) laser pulse has been investigated using single-shot based time-resolved resonant X-ray scattering at the X-ray Free Electron laser LCLS. A well-ordered stripe domain pattern as present in a thin CoPd alloy film has be...
1502.00786v1
2015-02-26
A Dictionary Approach to EBSD Indexing
We propose a framework for indexing of grain and sub-grain structures in electron backscatter diffraction (EBSD) images of polycrystalline materials. The framework is based on a previously introduced physics-based forward model by Callahan and De Graef (2013) relating measured patterns to grain orientations (Euler angl...
1502.07436v2
2015-03-01
Atomistic $k.p$ theory
Pseudopotentials, tight-binding models, and $k\cdot p$ theory have stood for many years as the standard techniques for computing electronic states in crystalline solids. Here we present the first new method in decades, which we call atomistic $k\cdot p$ theory. In its usual formulation, $k\cdot p$ theory has the advant...
1503.00217v3
2015-05-11
First-principles study of anisotropic thermoelectric transport properties of IV-VI semiconductor compounds SnSe and SnS
We conduct comprehensive investigations of both thermal and electrical transport properties of SnSe and SnS using first-principles calculations combined with the Boltzmann transport theory. Due to the distinct layered lattice structure, SnSe and SnS exhibit similarly anisotropic thermal and electrical behaviors. The cr...
1505.02601v3
2015-09-08
Pinning and elastic properties of vortex matter in highly strained Nb$_{75}$Zr$_{25}$: Analogy with viscous flow of disordered solids
We present the results of magnetization and magneto-transport measurements in the superconducting state of an as-cast Nb$_{75}$Zr$_{25}$ alloy. We also report the careful investigation of the microstructure of our sample at various length scales by using optical, scanning electron and transmission electron microscopies...
1509.02313v1
2015-11-16
Electric quadrupole interaction in cubic BCC alpha-Fe
Moessbauer transmission spectra for the 14.41-keV resonant line in 57Fe have been collected at room temperature by using 57Co(Rh) commercial source and alpha-Fe strain-free single crystal as an absorber. The absorber was magnetized to saturation in the absorber plane perpendicular to the gamma-ray beam axis applying sm...
1511.04933v4
2015-11-17
Pauli-limited superconductivity and antiferromagnetism in the heavy-fermion compound CeCo(In1-xZnx)5
We report on the anisotropic properties of Pauli-limited superconductivity (SC) and antiferromagnetism (AFM) in the solid solutions CeCo(In_{1-x}Zn_x)_5 (x<=0.07). In CeCo(In_{1-x}Zn_x)_5, the SC transition temperature T_c is continuously reduced from 2.3 K (x=0) to ~1.4 K (x=0.07) by doping Zn, and then the AFM order ...
1511.05241v1
2015-11-23
CPP Magnetoresistance of Magnetic Multilayers: A critical review
We present a comprehensive review of data and analysis of Giant (G) Magnetoresistance (MR) with Current-flow Perpendicular-to-layer-Planes (CPP-MR) of magnetic multilayers [F/N]n (n = number of repeats) with alternating nanoscale layers of ferromagnetic (F) and non-magnetic (N) metals. GMR, a large change in resistance...
1511.07387v1
2016-01-26
Radial Stark effect in (In,Ga)N nanowires
We study the luminescence of unintentionally doped and Si-doped In$_x$Ga$_{1-x}$N nanowires with a low In content (x<0.2) grown by molecular beam epitaxy on Si substrates. The emission band observed at 300 K from the unintentionally doped samples is centered at much lower energies (800 meV) than expected from the In co...
1601.07201v2
2016-02-02
Field-insensitive heavy fermion features and phase transition in the caged-structure quasi-skutterudite Sm$_3$Ru$_4$Ge$_{13}$
The robust field-insensitive heavy fermion features in Sm$_3$Ru$_4$Ge$_{13}$ and the magnetic phase transition at $T_N \approx$ 5~K are studied using magnetization $M(T)$, specific heat $C_p(T)$, resistivity $\rho(T)$ and thermal conductivity $\kappa_T(T)$. The average crystal structure of Sm$_3$Ru$_4$Ge$_{13}$ conform...
1602.00957v1
2016-05-17
Topologically close-packed phases in binary transition-metal compounds: matching high-throughput ab initio calculations to an empirical structure map
In steels and single-crystal superalloys the control of the formation of topologically close-packed (TCP) phases is critical for the performance of the material. The structural stability of TCP phases in multi-component transition-metal alloys may be rationalised in terms of the average valence-electron count $\bar{N}$...
1605.05188v1
2016-05-19
Simulation study of a new InGaN p-layer free Schottky based solar cell
On the road towards next generation high efficiency solar cells, the ternary Indium Gallium Nitride (InGaN) alloy is a good passenger since it allows to cover the whole solar spectrum through the change in its Indium composition. The choice of the main structure of the InGaN solar cell is however crucial. Obtaining a h...
1605.05936v1
2016-06-14
A crystallographic model of the {557} habit planes in low-carbon martensitic steels
Low-alloy steels are constituted of twenty-four variants of lath martensite that exhibit gradients of orientations from Kurdjumov-Sachs (KS) to Nishiyama-Wassermann (NW). They are structured into four packets on each of the common close-packed plane {111}fcc// {110}bcc; and each packet is composed of three blocks const...
1606.04257v2
2016-07-01
Trapping of solute atoms at grain boundaries in GdNi2
Lattice locations of 111In impurity probe atoms in intermetallic GdNi2 were studied as a function of alloy composition and temperature using perturbed angular correlation spectroscopy (PAC). Three nuclear quadrupole interaction signals were detected and their equilibrium site fractions were measured up to 700 oC. Two s...
1607.00160v1
2016-07-10
Eutectic colony formation in systems with interfacial energy anisotropy: A phase field study
Instability of a binary eutectic solidification front to morphological perturbations due to rejection of a ternary impurity leads to the formation of eutectic colonies. Whereas, the instability dynamics and the resultant mi- crostructural features are reasonably well understood for isotropic systems, several experiment...
1607.02722v3
2016-07-29
Superconductivity and non-Fermi-liquid behavior in the heavy-fermion compound CeCo$_{1-x}$Ni$_x$In$_5$
The effect of off-plane impurity on superconductivity and non-Fermi-liquid (NFL) behavior in the layered heavy-fermion compound CeCo$_{1-x}$Ni$_x$In$_5$ is investigated by specific heat, magnetization, and electrical resistivity measurements. These measurements reveal that the superconducting (SC) transition temperatur...
1607.08680v1
2016-09-15
Self-consistent mapping: Effect of local environment on formation of magnetic moment in alpha-FeSi2
We suggest here the method of the mapping of DFT calculations on the multiorbital model in a following way: the parameters of the formulated multiorbital model should be determined from the requirement that the self-consistent charge and spin densities found from the ab initio and model calculations have to be as close...
1609.04624v1
2016-10-03
The 10% Gd and Ti co-doped BiFeO$_3$: A promising multiferroic material
In this investigation, undoped BiFeO$_3$, Gd doped Bi$_{0.9}$Gd$_{0.1}$FeO$_3$, and Gd-Ti co-doped Bi$_{0.9}$Gd$_{0.1}$Fe$_{1-x}$Ti$_x$O$_3$ (x = 0.10, 0.20) materials were synthesized to report their multiferroic properties. The structural analysis and phase identification of these multiferroic ceramics were performed...
1610.00650v1
2017-01-03
Effects of particles on spinodal decomposition: A Phase field study
In this thesis, we study the interplay of phase separation and wetting in multicomponent systems. For this purpose, we have examined the phase separation pattern of a binary mixture (AB) in presence of stationary spherical particles (C) which prefers one of the components of the binary (say, A). Binary AB is composed o...
1701.01018v2
2017-03-29
Detailed experimental and numerical analysis of a cylindrical cup deep drawing: pros and cons of using solid-shell elements
The Swift test was originally proposed as a formability test to reproduce the conditions observed in deep drawing operations. This test consists on forming a cylindrical cup from a circular blank, using a flat bottom cylindrical punch and has been extensively studied using both analytical and numerical methods. This te...
1703.10126v1
2017-08-12
Modeling the complexity of acoustic emission spectra during intermittent plastic deformation: Power laws and multifractal spectra
Scale invariant power law distributions for acoustic emission signals are ubiquitous to several plastically deforming materials. However, power law distributions for the acoustic emission energies are reported in distinctly different plastically deforming situations such as in hcp and, fcc single and polycrystalline sa...
1708.03774v2
2017-08-20
Large anomalous Nernst and spin Nernst effects in noncollinear antiferromagnets Mn$_3X$ ($X$ = Sn, Ge, Ga)
Noncollinear antiferromagnets have recently been attracting considerable interest partly due to recent surprising discoveries of the anomalous Hall effect (AHE) in them and partly because they have promising applications in antiferromagnetic spintronics. Here we study the anomalous Nernst effect (ANE), a phenomenon hav...
1708.05933v3
2017-09-27
Recently synthesized (Zr1-xTix)2AlC (0 - x - 1) solid solutions: Theoretical study of the effects of M mixing on physical properties
The effects of M atomic species mixing on the physical properties of newly synthesized MAX phase (Zr1-xTix)2AlC solid solutions have been studied by means of density functional theory (DFT) calculations. The lattice constants in good accord with the experimental results, are found to decrease with Ti content. The elast...
1709.09505v2
2017-11-15
The Mpemba index and anomalous relaxation
The Mpemba effect is a counter-intuitive relaxation phenomenon, where a system prepared at a hot temperature cools down faster than an identical system initiated at a cold temperature when both are quenched to an even colder bath. Such non-monotonic relaxations were observed in various systems, including water, magneti...
1711.05829v3
2017-12-04
The MICROSCOPE mission: first results of a space test of the Equivalence Principle
According to the Weak Equivalence Principle, all bodies should fall at the same rate in a gravitational field. The MICROSCOPE satellite, launched in April 2016, aims to test its validity at the $10^{-15}$ precision level, by measuring the force required to maintain two test masses (of titanium and platinum alloys) exac...
1712.01176v2
2017-12-04
Error analysis of a fully discrete Morley finite element approximation for the Cahn-Hilliard equation
This paper proposes and analyzes the Morley element method for the Cahn-Hilliard equation. It is a fourth order nonlinear singular perturbation equation arises from the binary alloy problem in materials science, and its limit is proved to approach the Hele-Shaw flow. If the $L^2(\Omega)$ error estimate is considered di...
1712.01338v4
2017-12-08
Impact of intergrain spin transfer torques due to huge thermal gradients on the performance of heat assisted magnetic recording
Heat assisted magnetic recording (HAMR) is a new technology which uses temporary near field laser heating of the media during write to increase hard disk drive storage density. By using plasmonic antenna embedded in the write head, extremely high thermal gradient are created in the recording media (up to 10K/nm). State...
1712.03302v1
2018-03-08
Helical magnetic structure and the anomalous and topological Hall effects in epitaxial B20 Fe$_{1-y}$Co$_y$Ge films
Epitaxial films of the B20-structure alloy Fe$_{1-y}$Co$_y$Ge were grown by molecular beam epitaxy on Si (111) substrates. The magnetization varied smoothly from the bulk-like values of one Bohr magneton per Fe atom for FeGe to zero for non-magnetic CoGe. The chiral lattice structure leads to a Dzyaloshinskii-Moriya in...
1803.03281v2
2018-03-08
Impact of substrate temperature on magnetic properties of plasma-assisted molecular beam epitaxy grown (Ga,Mn)N
A range of high quality Ga1-xMnxN layers have been grown by molecular beam epitaxy with manganese concentration 0.2 < x < 10%, having the x value tuned by changing the growth temperature (Tg) between 700 and 590 {\deg}C, respectively. We present a systematic structural and microstructure characterization by atomic forc...
1803.03308v1
2018-03-14
Steel-Based Electrocatalysts for Efficient and Durable Oxygen Evolution in Acidic Media
High overpotentials, particularly an issue of common anode materials, hamper the process of water electrolysis for clean energy generation. Thanks to immense research efforts up to date oxygen evolution electrocatalysts based on earth-abundant elements work efficiently and stably in neutral and alkaline regimes. Howeve...
1803.05772v1
2018-03-29
Proposal for a micromagnetic standard problem for materials with Dzyaloshinskii-Moriya interaction
Understanding the role of the Dzyaloshinskii-Moriya interaction (DMI) for the formation of helimagnetic order, as well as the emergence of skyrmions in magnetic systems that lack inversion symmetry, has found increasing interest due to the significant potential for novel spin based technologies. Candidate materials to ...
1803.11174v1
2018-05-09
Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): a DFT calculation
The electronic band structures along with Fermi surface, anisotropy, Vickers hardness, analysis of Mulliken populations, optical and thermodynamic properties were studied for the first time. The optimized unit cell parameters are compared with available theoretical and experimental results and a reasonable agreement is...
1805.03392v2
2018-06-12
Bayesian Uncertainty Quantification and Information Fusion in CALPHAD-based Thermodynamic Modeling
Calculation of phase diagrams is one of the fundamental tools in alloy design---more specifically under the framework of Integrated Computational Materials Engineering. Uncertainty quantification of phase diagrams is the first step required to provide confidence for decision making in property- or performance-based des...
1806.05769v3
2018-09-06
Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys
Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the difficulty in experimentally probing such rapid dynamics. Here, we find evi...
1809.02076v2
2018-09-13
Optimization of nonhomogeneous indium-gallium-nitride Schottky-barrier thin-film solar cells
A two-dimensional model was developed to simulate the optoelectronic characteristics of indium-gallium-nitride (InGaN), thin-film, Schottky-barrier solar cells. The solar cells comprise a window, designed to reduce the reflection of incident light, Schottky-barrier and ohmic front electrodes, an n-doped InGaN wafer, an...
1809.06347v1
2018-09-19
Contribution of top barrier materials to high mobility in near-surface InAs quantum wells grown on GaSb(001)
Near-surface InAs two-dimensional electron gas (2DEG) systems have great potential for realizing networks of multiple Majorana zero modes towards a scalable topological quantum computer. Improving mobility in the near-surface 2DEGs is beneficial for stable topological superconducting states as well as for correlation o...
1809.06971v1
2018-09-20
Morphological, nanostructural, and compositional evolution during phase separation of a model Ni-Al-Mo superalloy: Atom-probe tomographic experiments and lattice-kinetic Monte Carlo simulations
The details of phase separation of a Ni-6.5Al-9.9Mo aged at 978 K for aging times ranging from 0.125 to 1024 h are investigated by atom-probe tomography and lattice-kinetic Monte Carlo (LKMC) simulations. On the basis of the temporal evolution of the nanostructure, three experimental regimes are identified: (1) concomi...
1809.07438v1
2018-11-01
Extreme Broadband Transparent Optical Phase Change Materials for High-Performance Nonvolatile Photonics
Optical phase change materials (O-PCMs), a unique group of materials featuring drastic optical property contrast upon solid-state phase transition, have found widespread adoption in photonic switches and routers, reconfigurable meta-optics, reflective display, and optical neuromorphic computers. Current phase change ma...
1811.00526v2
2018-11-14
Single shot time-resolved magnetic x-ray absorption at a Free Electron Laser
Ultrafast dynamics are generally investigated using stroboscopic pump-probe measurements, which characterize the sample properties for a single, specific time delay. These measurements are then repeated for a series of discrete time delays to reconstruct the overall time trace of the process. As a consequence, this app...
1811.05917v1
2018-11-27
Reversible magnetic switching of high-spin molecules on a giant Rashba surface
The quantum mechanical screening of a spin via conduction electrons depends sensitively on the environment seen by the magnetic impurity. A high degree of responsiveness can be obtained with metal complexes, as the embedding of a metal ion into an organic molecule prevents intercalation or alloying and allows for a goo...
1811.11294v1
2019-11-13
Electronic structure investigation of GdNi using X-ray absorption, magnetic circular dichroism and hard x-ray photoemission spectroscopy
GdNi is a ferrimagnetic material with a Curie temperature Tc = 69 K which exhibits a large magnetocaloric effect, making it useful for magnetic refrigerator applications. We investigate the electronic structure of GdNi by carrying out x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) at T...
1911.05306v2
2020-01-06
Field-angle resolved magnetic excitations as a probe of hidden-order symmetry in CeB6
In contrast to magnetic order formed by electrons' dipolar moments, ordering phenomena associated with higher-order multipoles (quadrupoles, octupoles, etc.) are more difficult to characterize because of the limited choice of experimental probes that can distinguish different multipolar moments. The heavy-fermion compo...
2001.01672v1
2020-01-07
Electronic structure of $β$-SiAlON: effect of varying Al/O concentration at finite temperatures relevant for thermal quenchin
$\beta$-Si$_{6-z}$Al$_{z}$O$_{z}$N$_{8-z}$ is a prominent example of systems suitable as hosts for creating materials for light-emitting diodes. In this work, the electronic structure of a series of ordered and disordered $\beta$-Si$_{6-z}$Al$_{z}$O$_{z}$N$_{8-z}$ systems is investigated by means of ab initio calculati...
2001.02150v2
2021-07-21
Comprehensive Study of Lithium Adsorptionand Diffusion on Janus Mo/WXY (X, Y= S,Se, Te) using First Principles and MachineLearning Approaches
The structural asymmetry of two-dimensional (2D) Janus transition metal dichalcogenides (TMDs) produces internal dipole moments that result in interesting electronic properties. These properties differ from the regular (symmetric) TMD structures that the Janus structures are derived from. In this study, we, at first, e...
2107.10215v1
2021-07-29
Addressing materials' microstructure diversity using transfer learning
Materials' microstructures are signatures of their alloying composition and processing history. Therefore, microstructures exist in a wide variety. As materials become increasingly complex to comply with engineering demands, advanced computer vision (CV) approaches such as deep learning (DL) inevitably gain relevance f...
2107.13841v1
2017-04-24
Distinct Correlation between the Vibrational and Thermal Transport Properties of Group \textrm{VA} Monolayer Crystals
The investigation of thermal transport properties of novel two dimensional materials is crucially important in order to assess their potential to be used in future technological applications, such as thermoelectric power generation. In this respect, lattice thermal transport properties of monolayer structures of the gr...
1704.07120v2
2017-05-04
Application of Finite Element, Phase-field, and CALPHAD-based Methods to Additive Manufacturing of Ni-based Superalloys
Numerical simulations are used in this work to investigate aspects of microstructure and microsegregation during rapid solidification of a Ni-based superalloy in a laser powder bed fusion additive manufacturing process. Thermal modeling by finite element analysis simulates the laser melt pool, with surface temperatures...
1705.02016v1
2018-07-17
CCAT-prime: a novel telescope for submillimeter astronomy
The CCAT-prime telescope is a 6-meter aperture, crossed-Dragone telescope, designed for millimeter and sub-millimeter wavelength observations. It will be located at an altitude of 5600 meters, just below the summit of Cerro Chajnantor in the high Atacama region of Chile. The telescope's unobscured optics deliver a fiel...
1807.06675v1
2018-10-24
Long spin coherence length and bulk-like spin-orbit torque in ferrimagnetic multilayers
Ferromagnetic spintronics has been a main focus as it offers non-volatile memory and logic applications through current-induced spin-transfer torques. Enabling wider applications of such magnetic devices requires a lower switching current for a smaller cell while keeping the thermal stability of magnetic cells for non-...
1810.10404v1
2019-04-05
Design of a high power production target for the Beam Dump Facility at CERN
The Beam Dump Facility (BDF) project is a proposed general-purpose facility at CERN, dedicated to beam dump and fixed target experiments. In its initial phase, the facility is foreseen to be exploited by the Search for Hidden Particles (SHiP) experiment. Physics requirements call for a pulsed 400 GeV/c proton beam as w...
1904.03074v2
2019-04-22
Vacancy complexes in nonequilibrium germanium-tin semiconductors
Understanding the nature and behavior of vacancy-like defects in epitaxial GeSn metastable alloys is crucial to elucidate the structural and optoelectronic properties of these emerging semiconductors. The formation of vacancies and their complexes is expected to be promoted by the relatively low substrate temperature r...
1904.09909v1