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2022-06-23
Microstructural Design via Spinodal-Mediated Phase Transformation Pathways in High-Entropy Alloys (HEAs) using Phase-Field Modelling
Understanding the phase transformation pathways (PTPs) and microstructural evolution in multi-phase HEAs will aid alloy and process designs to tailor the microstructures for specific engineering applications. In this work, we study microstructural evolution in two-phase HEAs where a disordered parent phase separates in...
2206.11983v1
2022-07-08
Ab-Initio Simulation of Field Evaporation
A new simulation approach of field evaporation is presented. The model combines classical electrostatics with molecular dynamics (MD) simulations. Unlike previous atomic-level simulation approaches, our method does not rely on an evaporation criterion based on thermal activation theory, instead, electric-field-induced ...
2207.03958v2
2022-07-17
Understanding Mechanical Characteristics of FeNiCrCoCu HEA in Nanoscale Laser Powder Bed Fusion via Molecular Dynamics
The concept of alloying multiple principal elements at high concentrations has led to the development of High Entropy Alloys (HEAs) with exceptional mechanical properties, making them the focus of major recent scientific endeavors. Geometrically complex HEAs with tailored microstructural characteristics can be produced...
2207.08091v1
2022-07-11
Analysis and design of bistable and thermally reversible metamaterials inspired by shape-memory alloys
In this work, we study lattice structures that exhibit a bistable behavior, i. e., they can snap from one stable state to another, and are also completely reversible, capable of reverting back to its original state through a heat treatment. We design this behavior by constructing lattice structures using networks of no...
2207.08722v1
2022-07-30
Atomistic simulations of ductile failure in a b.c.c. high entropy alloy
Ductile failure is studied in a bcc HfNbTaZr High Entropy Alloy (HEA) with a pre-existing void. Using molecular dynamics simulations of uniaxial tensile tests, we explore the effect of void radius on the elastic modulus and yield stress. The elastic modulus scales with porosity as in closed-cell foams. The critical str...
2208.00234v1
2022-08-18
A systematic study of spin-dependent recombination in GaAs$_{1-x}$N$_x$ as a function of nitrogen content
A systematic study of spin-dependent recombination (SDR) under steady-state optical pumping conditions in dilute nitride semiconductors as a function of nitrogen content is reported. The alloy content is determined by a fit of the photoluminescence (PL) intensity using a Roosbroeck-Shockley relation and verified by a s...
2208.08785v1
2022-08-26
Second-order topological magneto-optical effects in noncoplanar antiferromagnets
The second-order magneto-optical effects, represented by Voigt and Sch\"{a}fer-Hubert effects, are effective methods to detect the spin textures in antiferromagnets, whereas the previous studies are usually limited to collinear antiferromagnets. In noncollinear antiferromagnets, the spin textures characterized by spin ...
2208.12638v1
2022-08-28
High entropy van der Waals materials (Review article)
By breaking the restrictions on traditional alloying strategy, the high entropy concept has promoted the exploration of the central area of phase space, thus broadening the horizon of alloy exploitation. This review highlights the marriage of the high entropy concept and van der Waals systems to form a new family of ma...
2208.13313v1
2022-08-29
Room temperature spin-orbit torque efficiency and magnetization switching in SrRuO3-based heterostructures
Spin-orbit torques (SOTs) from transition metal oxides (TMOs) in conjunction with magnetic materials have recently attracted tremendous attention for realizing high-efficient spintronic devices. SrRuO3 is a promising candidate among TMOs due to its large and tunable SOT-efficiency as well as high conductivity and chemi...
2208.13574v1
2022-09-01
Computing Grain Boundary 'Phase' Diagrams
Grain boundaries (GBs) can be treated as two-dimensional (2-D) interfacial phases (also called 'complexions') that can undergo interfacial phase-like transitions. As bulk phase diagrams and calculation of phase diagram (CALPHAD) methods are a foundation for modern materials science, we propose to extend them to GBs to ...
2209.00754v1
2022-09-08
Effects of the local chemical environment on vacancy diffusion in multi-principal element alloys
Multi-principal element alloys (MPEAs) are exciting systems showing remarkable properties compared to conventional materials due to their exceedingly large compositional space and spatially varying chemical environment. However, predicting fundamental properties from the local chemical environment is challenging due to...
2209.04010v1
2022-09-21
Classical and Machine Learning Interatomic Potentials for BCC Vanadium
BCC transition metals (TMs) exhibit complex temperature and strain-rate dependent plastic deformation behaviour controlled by individual crystal lattice defects. Classical empirical and semi-empirical interatomic potentials have limited capability in modelling defect properties such as the screw dislocation core struct...
2209.12322v1
2022-10-05
Magnetic, structural and magnetocaloric properties of Y$_{0.9}$Gd$_{0.1}$Fe$_{2}$H$_{x}$ hydrides
At 300 K, Y$_{0.9}$Gd$_{0.1}$Fe$_{2}$H$_{x}$ hydrides crystallize sequentially with increasing H concentration in various structures related to a lowering of the cubic MgCu$_{2}$ type structure of the parent alloy: cubic C1, monoclinic M1, cubic C2, monoclinic M2, cubic C3, orthorhombic O. Above 300 K, they undergo a f...
2210.02262v1
2022-10-09
Hyperactive Learning (HAL) for Data-Driven Interatomic Potentials
Data-driven interatomic potentials have emerged as a powerful class of surrogate models for {\it ab initio} potential energy surfaces that are able to reliably predict macroscopic properties with experimental accuracy. In generating accurate and transferable potentials the most time-consuming and arguably most importan...
2210.04225v2
2022-10-11
Influence of chemistry and structure on interfacial segregation in NbMoTaW with high-throughput atomistic simulations
Refractory multi-principal element alloys exhibiting promising mechanical properties such as excellent strength retention at elevated temperatures have been attracting increasing attention. Although their inherent chemical complexity is considered a defining feature, a challenge arises in predicting local chemical orde...
2210.05654v2
2022-10-17
The electronic disorder landscape of mixed halide perovskites
Bandgap tunability of lead mixed-halide perovskites makes them promising candidates for various applications in optoelectronics since they exhibit sharp optical absorption onsets despite the presence of disorder from halide alloying. Here we use localization landscape theory to reveal that the static disorder due to co...
2210.08705v1
2022-10-20
Kinetics of transformation, border of metastable miscibility gap in Fe-Cr alloy and limit of Cr solubility in iron at 858 K
The study was aimed at determination of the position of the Fe-rich border of the metastable miscibility gap (MMG) and of the solubility limit of Cr in iron at 858 K. Towards this end a Fe73.7Cr26.3 alloy was isothermally annealed at 858 K in vacuum up to 8144 hours and M\"ossbauer spectra were recorded at room tempera...
2210.11550v1
2022-10-25
Ab-initio Prediction of Ultra-Wide Band Gap B$_x$Al$_{1-x}$N Materials
Ultra-wide band gap (UWBG) materials are poised to play an important role in the future of power electronics. Devices made from UWBG materials are expected to operate at higher voltages, frequencies, and temperatures than current silicon and silicon carbide based devices; and can even lead to significant miniaturizatio...
2210.14375v4
2022-10-30
The creep deformation of a new nickel-base alloy-by-design studied using synchrotron X-ray diffraction
Understanding the creep mechanisms and deformation response at different stresses and temperatures is crucial for design using nickel-base superalloys for high-temperature applications. In this study, the creep behaviour of a newly designed superalloy (nominated Alloy 11) at different stress and temperature was systema...
2210.16840v2
2022-11-05
Designing magnetic properties in CrSBr through hydrostatic pressure and ligand substitution
The ability to control magnetic properties of materials is crucial for fundamental research and underpins many information technologies. In this context, two-dimensional materials are a particularly exciting platform due to their high degree of tunability and ease of implementation into nanoscale devices. Here we repor...
2211.02788v1
2022-11-07
Solidification of the Glass-Forming Al86Ni2Co6Gd6 Melt under High Pressure
High pressures allow the synthesis of new metastable compounds that remain intact for a sufficiently long time at normal conditions. Until now, it has not been fully understood how pressure, glass-forming ability and solidification of liquids are interconnected. We have investigated the structure of the glass-forming e...
2211.03513v1
2022-11-15
Tunable magnetic and magnetocaloric properties by thermal annealing in ErCo2 atomized particles
Processing magnetocaloric materials into magnetic refrigerants with appropriate shapes is essential for the development of magnetic refrigeration systems. In this context, the impact of processing on the physical properties of magnetocaloric materials is one of the important issues. Here, we investigate the crystallogr...
2211.08069v1
2022-11-17
Short-range order and compositional phase stability in refractory high-entropy alloys via first principles theory and atomistic modelling: NbMoTa, NbMoTaW and VNbMoTaW
Using an all-electron, first principles, Landau-type theory, we study the nature of short-range order and compositional phase stability in equiatomic refractory high entropy alloys, NbMoTa, NbMoTaW, and VNbMoTaW. We also investigate selected binary subsystems to provide insight into the physical mechanisms driving orde...
2211.09911v3
2022-11-22
Accelerated Solutions of Coupled Phase-Field Problems using Generative Adversarial Networks
Multiphysics problems such as multicomponent diffusion, phase transformations in multiphase systems and alloy solidification involve numerical solution of a coupled system of nonlinear partial differential equations (PDEs). Numerical solutions of these PDEs using mesh-based methods require spatiotemporal discretization...
2211.12084v2
2022-11-24
Short-ranged ordering for improved mean-field simulation of disordered media: insights from refractory-metal high-entropy alloy carbonitrides
Multi-principal element materials (MPEMs) have been attracting a rapidly growing interest due to their exceptional performance under extreme conditions, from cryogenic conditions to extreme-high temperatures and pressures. Despite the simple conceptual premise behind their formation, computational high-throughput first...
2211.13805v1
2022-12-05
Disordered Hyperuniform Solid State Materials
Disordered hyperuniform (DHU) states are recently discovered exotic states of condensed matter. DHU systems are similar to liquids or glasses in that they are statistically isotropic and lack conventional long-range translational and orientational order. On the other hand, they completely suppress normalized infinite-w...
2212.02464v1
2023-01-04
A computationally efficient and mechanically compatible multi-phase-field model applied to coherently stressed three-phase solids
Engineering alloys generally exhibit multi-phase microstructures. For simulating their microstructure evolution during solid-state phase transformation, CALPHAD-guided multi-phase-field models coupled with micro-mechanics have proven to be a reliable simulation tool. Nevertheless, their efficiency and accuracy still de...
2301.01747v1
2023-01-09
Multiscale simulations of growth-dominated Sb$_2$Te phase-change material for non-volatile photonic applications
Chalcogenide phase-change materials (PCMs) are widely applied in electronic and photonic applications, such as non-volatile memory and neuro-inspired computing. Doped Sb$_2$Te alloys are now gaining increasing attention for on-chip photonic applications, due to their growth-driven crystallization features. However, it ...
2301.03146v2
2023-01-20
Simulation of dendritic-eutectic growth with the phase-field method
Solidification is an important process in many alloy processing routes. The solidified microstructure of alloys is usually made up of dendrites, eutectics or a combination of both. The evolving morphologies are largely determined by the solidification process and thus many materials properties are dependent on the proc...
2301.08593v2
2023-01-25
Bioabsorbable WE43 Mg alloy wires modified by continuous plasma-electrolytic oxidation for implant applications. Part I: processing, microstructure and mechanical properties
In our work, a novel processing strategy for the continuous fabrication and surface modification of wires from Magnesium alloy WE43 by means of plasma-electrolytic oxidation (PEO) is presented. In the first step, wires with a strong basal texture and small grain size ($\approx$ 1 $\mu$m) were manufactured by combined c...
2301.10479v1
2023-01-26
Metalorganic Chemical Vapor Deposition of \b{eta}-(AlxGa1-x)2O3 thin films on (001) \b{eta}-Ga2O3 substrates
Phase pure \b{eta}-(AlxGa1-x)2O3 thin films are grown on (001) oriented \b{eta}-Ga2O3 substrates via metalorganic chemical vapor deposition (MOCVD). By systematically tuning the precursor molar flow rates, the epitaxial growth of coherently strained \b{eta}-(AlxGa1-x)2O3 films are demonstrated with up to 25% Al composi...
2301.10897v1
2023-01-27
Machine-guided Design of Oxidation Resistant Superconductors for Quantum Information Applications
Decoherence in superconducting qubits has long been attributed to two level systems arising from the surfaces and interfaces present in real devices. A recent significant step in reducing decoherence was the replacement of superconducting niobium by superconducting tantalum, resulting in a tripling of transmon qubit li...
2301.11543v1
2023-01-27
A ferromagnetic Eu-Pt surface compound grown below hexagonal boron nitride
One of the fundamental applications for monolayer-thick 2D materials is their use as protective layers of metal surfaces and in-situ intercalated reactive materials in ambient conditions. Here we investigate the structural, electronic, and magnetic properties, as well as the chemical stability in air of a very reactive...
2301.11837v2
2023-02-17
Complex strengthening mechanisms in nanocrystalline Ni-Mo alloys revealed by a machine-learning interatomic potential
A nanocrystalline metal's strength increases significantly as its grain size decreases, a phenomenon known as the Hall-Petch relation. Such relation, however, breaks down when the grains become too small. Experimental studies have circumvented this problem in a set of Ni-Mo alloys by stabilizing the grain boundaries (G...
2302.08698v1
2023-03-03
Machine learning of twin/matrix interfaces from local stress field
Twinning is an important deformation mode in plastically deformed hexagonal close-packed materials. The extremely high twin growth rates at the nanoscale make atomistic simulations an attractive method for investigating the role of individual twin/matrix interfaces such as twin boundaries and basal-prismatic interfaces...
2303.02247v1
2023-03-15
Metallurgical synthesis methods for Mg-Al-Ca scientific model materials
Mg-based alloys are industrially used for structural applications, both as solid solutions alloys and as composites containing intermetallic compounds. However, a further development in terms of mechanical properties requires the investigation of underlying causalities between synthesis, processing and microstructure t...
2303.08523v1
2023-03-16
Morphological stability of solid-liquid interfaces under additive manufacturing conditions
Understanding rapid solidification behavior at velocities relevant to additive manufacturing (AM) is critical to controlling microstructure selection. Although in-situ visualization of solidification dynamics is now possible, systematic studies under AM conditions with microstructural outcomes compared to solidificatio...
2303.09137v1
2023-03-24
A multi-stage, first-order phase transition in LaFe11.8Si1.2: interplay between the structural, magnetic and electronic degrees of freedom
Alloys with a first-order magnetic transition are central to solid-state refrigeration technology, sensors and actuators, or spintronic devices. The discontinuous nature of the transition in these materials is a consequence of the coupling between the magnetic, electronic and structural subsystems, but in a real experi...
2303.13836v2
2023-04-12
The emergence of interface states in graphene/transition metal dichalcogenides heterostructure with lateral interface
The relative strength of different proximity spin-orbit couplings in graphene on transition metal dichalcogenides (TMDC) can be tuned via the metal composition in the TMDC layer. While Gr/MoSe$_2$, has a normal gap, proximity to WSe$_2$ instead leads to valley-Zeeman-driven inverted bands. Although the $\mathbb{Z}_2$ i...
2304.06086v1
2023-04-18
A machine learning framework for quantifying chemical segregation and microstructural features in atom probe tomography data
Atom probe tomography (APT) is ideally suited to characterize and understand the interplay of chemical segregation and microstructure in modern multicomponent materials. Yet, the quantitative analysis typically relies on human expertise to define regions of interest. We introduce a computationally efficient, multistage...
2304.08761v1
2023-05-03
Microwave loss characterization using multi-mode superconducting resonators
Measuring the losses arising from different materials and interfaces is crucial to improving the coherence of superconducting quantum circuits. Although this has been of interest for a long time, current studies can either only provide bounds to those losses, or require several devices for a complete characterization. ...
2305.01872v1
2023-06-09
Deformation-induced homogenization of the multi-phase senary high-entropy alloy MoNbTaTiVZr processed by high-pressure torsion
Dendritic microstructures are frequently observed in as-solidified refractory high-entropy alloys (RHEAs), and their homogenization typically requires a long-term heat treatment at extremely high temperatures. High-pressure torsion (HPT) has been shown to be capable of mixing immiscible systems at room temperature, and...
2306.05711v1
2023-06-13
Analysis of hydrogen diffusion in the three stage electro-permeation test
The presence of hydrogen traps within a metallic alloy influences the rate of hydrogen diffusion. The electro-permeation (EP) test can be used to assess this: the permeation of hydrogen through a thin metallic sheet is measured by suitable control of hydrogen concentration on the front face and by recording the flux of...
2306.07666v1
2023-06-17
Machine learning search for stable binary Sn alloys with Na, Ca, Cu, Pd, and Ag
We present our findings of a large-scale screening for new synthesizable materials in five M-Sn binaries, M = Na, Ca, Cu, Pd, and Ag. The focus on these systems was motivated by the known richness of M-Sn properties with potential applications in energy storage, electronics packaging, and superconductivity. For the sys...
2306.10223v3
2023-06-19
Substitutional Alloying Using Crystal Graph Neural Networks
Materials discovery, especially for applications that require extreme operating conditions, requires extensive testing that naturally limits the ability to inquire the wealth of possible compositions. Machine Learning (ML) has nowadays a well established role in facilitating this effort in systematic ways. The increasi...
2306.10766v1
2023-06-21
An Analytical Model to Quantify the Local Lattice Distortion of Refractory High Entropy Alloys
Local lattice distortion (LLD) of high entropy alloys (HEAs) especially refractory HEAs, which is different from one lattice site to another, determines the mechanical properties of HEAs such as yield strength and radiation resistance, and is crucial to modulating catalytic activity of HEAs via the atomic strain. In pa...
2306.11959v1
2023-06-27
Non-invasive digital etching of van der Waals semiconductors
The capability to finely tailor material thickness with simultaneous atomic precision and non-invasivity would be useful for constructing quantum platforms and post-Moore microelectronics. However, it remains challenging to attain synchronized controls over tailoring selectivity and precision. Here we report a protocol...
2306.15139v1
2023-07-03
Yielding transition of amorphous solids in the presence of aspherical impurities
Understanding the mechanical properties of amorphous solids has been a field of intense research not only for the zoo of interesting phenomena one observes once these solids are subjected to external deformations but also for their importance in industrial applications. Amorphous solids are known to have higher yield s...
2307.01002v1
2023-08-01
Dose and compositional dependence of irradiation-induced property change in FeCr
Ferritic/martensitic steels will be used as structural components in next generation nuclear reactors. Their successful operation relies on an understanding of irradiation-induced defect behaviour in the material. In this study, Fe and FeCr alloys (3-12%Cr) were irradiated with 20 MeV Fe-ions at 313 K to doses ranging ...
2308.00771v2
2023-08-05
FAST: Font-Agnostic Scene Text Editing
Scene Text Editing (STE) is a challenging research problem, and it aims to modify existing texts in an image while preserving the background and the font style of the original text of the image. Due to its various real-life applications, researchers have explored several approaches toward STE in recent years. However, ...
2308.02905v1
2023-08-06
Superconductivity near the Mott-Ioffe-Regel limit in the high-entropy alloy superconductor (ScZrNb)$_{1-x}$(RhPd)$_x$ with a CsCl-type lattice
Theoretical analysis of the electronic structure of the high-entropy-type superconductor (ScZrNb)$_{1-x}$(RhPd)$_x$, $x \in (0.35, 0.45)$ is presented. The studied material is a partially ordered CsCl-type structure, with two sublattices, randomly occupied by Sc, Zr, Nb (first sublattice) and Nb, Rh, and Pd (second sub...
2308.03153v1
2023-08-10
Predictions and correlation analyses of Ellingham diagrams in binary oxides
Knowing oxide-forming ability is vital to gain desired or avoid deleterious oxides formation through tuning oxidizing environment and materials chemistry. Here, we have conducted a comprehensive thermodynamic analysis of 137 binary oxides using the presently predicted Ellingham diagrams. It is found that the active ele...
2308.05837v1
2023-08-30
Machine-Learning-Assisted Construction of Ternary Convex Hull Diagrams
In the search for novel intermetallic ternary alloys, much of the effort goes into performing a large number of ab-initio calculations covering a wide range of compositions and structures. These are essential to build a reliable convex hull diagram. While density functional theory (DFT) provides accurate predictions fo...
2308.15907v1
2023-08-30
Chemical heterogeneity enhances hydrogen resistance in high-strength steels
When H, the lightest, smallest and most abundant atom in the universe, makes its way into a high-strength alloy (>650 MPa), the material's load-bearing capacity is abruptly lost. This phenomenon, known as H embrittlement, was responsible for the catastrophic and unpredictable failure of large engineering structures in ...
2308.16048v1
2023-09-02
A Boosted Machine Learning Framework for the Improvement of Phase and Crystal Structure Prediction of High Entropy Alloys Using Thermodynamic and Configurational Parameters
The reason behind the remarkable properties of High-Entropy Alloys (HEAs) is rooted in the diverse phases and the crystal structures they contain. In the realm of material informatics, employing machine learning (ML) techniques to classify phases and crystal structures of HEAs has gained considerable significance. In t...
2309.00993v2
2023-09-16
A Modelling study of Electron transport in GaN/AlGaN superlattices using Monte Carlo simulation
Electron transport in GaN/AlxGa1-xN superlattices is investigated using a single particle Monte Carlo approach. To establish the band structure required GaN, AlN and their ternary alloy are investigated using a single electron Monte Carlo approach and a 3-band approximation to the full band structure. The interplay of ...
2309.09029v1
2023-09-24
Approaching Ferrite-Based Exchange-Coupled Nanocomposites as Permanent Magnets
During the past decade, CoFe2O4 (hard)/Co-Fe alloy (soft) magnetic nanocomposites have been routinely prepared by partial reduction of CoFe2O4 nanoparticles. Monoxide (i.e., FeO or CoO) has often been detected as a byproduct of the reduction, although it remains unclear whether the formation of this phase occurs during...
2309.13729v1
2023-09-29
Magnetism, transport and atomic structure of amorphous binary YxCo1-x alloys
Sputtered thin films of binary YxCo1-x with 0 < x < 0.54 and thickness 15 nm are investigated to help understand the ferromagnetism of cobalt in amorphous rare-earth cobalt alloys. The magnetic moment per cobalt falls to zero at x0 = 0.50, where the appearance of magnetism is marked by a para-process with a dimensionle...
2309.16996v1
2023-10-02
Harnessing the Power of Multi-Lingual Datasets for Pre-training: Towards Enhancing Text Spotting Performance
The adaptation capability to a wide range of domains is crucial for scene text spotting models when deployed to real-world conditions. However, existing state-of-the-art (SOTA) approaches usually incorporate scene text detection and recognition simply by pretraining on natural scene text datasets, which do not directly...
2310.00917v4
2023-10-07
FEcMD: A multi-physics and multi-scale computational program for electron emission characteristics dynamically coupled with atomic structure in metal nano-emitters
Field emission coupled with molecular dynamics simulation (FEcMD) software package is a computational tool for studying the electron emission characteristics and the atomic structure evolution of micro- and nano-protrusions made of pure metals or multi-component alloys by means of multi-physics and multi-scale methodol...
2310.04751v1
2023-10-09
Efficient Modeling and Simulation of Chemo-Elasto-Plastically Coupled Battery Active Particles
As an anode material for lithium-ion batteries, amorphous silicon offers a significantly higher energy density than the graphite anodes currently used. Alloying reactions of lithium and silicon, however, induce large deformation and lead to volume changes up to 300%. We formulate a thermodynamically consistent continuu...
2310.05440v2
2023-10-11
Mid-Infrared Detectors and Imagers Integrating All-Group IV Nanowires
Cost-effective mid-wave infrared (MWIR) optoelectronic devices are of utmost importance to a plethora of applications such as night vision, thermal sensing, autonomous vehicles, free-space communication, and spectroscopy. To this end, leveraging the ubiquitous silicon-based processing has emerged as a powerful strategy...
2310.07833v1
2023-10-19
Discovering Novel Halide Perovskite Alloys using Multi-Fidelity Machine Learning and Genetic Algorithm
Expanding the pool of stable halide perovskites with attractive optoelectronic properties is crucial to addressing current limitations in their performance as photovoltaic (PV) absorbers. In this article, we demonstrate how a high-throughput density functional theory (DFT) dataset of halide perovskite alloys can be use...
2310.13153v1
2023-10-31
Unlocking ultrastrong high-temperature ceramics: Beyond Equimolar Compositions in High Entropy Nitrides
Traditionally, increasing compositional complexity and chemical diversity of high entropy alloy ceramics whilst maintaining a stable single-phase solid solution has been a primary design strategy for the development of new ceramics. However, only a handful have shown properties that justify the increased alloying conte...
2310.20441v2
2023-11-03
Alloying Effects on the Microstructure and Properties of Laser Additively Manufactured Tungsten Materials
A large body of literature within the additive manufacturing (AM) community has focused on successfully creating stable tungsten (W) microstructures due to significant interest in its application for extreme environments. However, solidification cracking and additional embrittling features at grain boundaries have resu...
2311.02034v1
2023-11-12
Probing the superconducting pairing of the La$_{4}$Be$_{33}$Pt$_{16}$ alloy via muon-spin spectroscopy
We report a study of the superconducting pairing of the noncentrosymmetric La$_{4}$Be$_{33}$Pt$_{16}$ alloy using muon-spin rotation and relaxation ({\textmu}SR) technique. Below $T_c = 2.4$ K, La$_{4}$Be$_{33}$Pt$_{16}$ exhibits bulk superconductivity (SC), here characterized by heat-capacity and magnetic-susceptibili...
2311.06841v1
2023-11-06
Performance Prediction of Data-Driven Knowledge summarization of High Entropy Alloys (HEAs) literature implementing Natural Language Processing algorithms
The ability to interpret spoken language is connected to natural language processing. It involves teaching the AI how words relate to one another, how they are meant to be used, and in what settings. The goal of natural language processing (NLP) is to get a machine intelligence to process words the same way a human bra...
2311.07584v1
2023-11-21
Ab initio framework for deciphering trade-off relationships in multi-component alloys
While first-principles methods have been successfully applied to characterize individual properties of multi-principal element alloys (MPEA), their use to search for optimal trade-offs between competing properties is hampered by high computational demands. In this work, we present a novel framework to explore Pareto-op...
2311.12642v1
2023-12-01
Hydrogen-induced switching of perpendicular magnetic anisotropy in amorphous ferrimagnetic thin films
Unraveling the mechanisms responsible for perpendicular magnetic anisotropy (PMA) in amorphous rare earth-transition metal alloys has proven challenging, primarily due to the intrinsic complexity of the amorphous structure. Here, we investigated the atomic origin of PMA by applying an approach of voltage-driven hydroge...
2312.00643v1
2023-12-22
FeMnNiAlCr High Entropy Alloys with High-Efficiency Surface Oxide Solar Absorbers for Concentrating Solar Power Systems
High entropy alloys (HEAs) have attracted substantial interest in recent years. Thus far, most investigations have focused on their applications as structural materials rather than functional materials. In this paper, we show that FeMnNiAlCr HEAs can potentially be applied as both a structural and functional material f...
2312.15076v1
2024-01-09
Coexistence of large anomalous Nernst effect and large coercive force in amorphous ferrimagnetic TbCo alloy films
The Anomalous Nernst Effect (ANE) has garnered significant interest for practical applications, particularly in energy harvesting and heat flux sensing. For these applications, it is crucial for the module to operate without an external magnetic field, necessitating a combination of a large ANE and a substantial coerci...
2401.04445v1
2024-01-10
Exploring the formation of gold/silver nanoalloys with gas-phase synthesis and machine-learning assisted simulations
While nanoalloys are of paramount scientific and practical interests, the main processes leading to their formation are still poorly understood. Key structural features in the alloy systems, including crystal phase, chemical ordering, and morphology, are challenging to control at the nanoscale, making it difficult to t...
2401.05106v1
2024-01-23
Splitting Instability in Superalloys: A Phase-Field Study
Precipitation-strengthened alloys, such as Ni-base, Co-base and Fe-base superalloys, show the development of dendrite-like precipitates in the solid state during aging at near-$\gamma^{\prime}$ solvus temperatures. These features arise out of a diffusive instability wherein, due to the point effect of diffusion, morpho...
2401.13151v1
2024-01-29
Atomistic-Level Analysis of Nanoindentation-Induced Plasticity in Arc--Melted NiFeCrCo Alloys: The role of stacking faults
Concentrated solid solution alloys (CSAs) have attracted attention for their promising properties; however, current manufacturing methods face challenges in complexity, high costs, and limited scalability, raising concerns about industrial viability. The prevalent technique, arc melting, yields high-purity samples with...
2401.16065v1
2024-02-01
Element-specific and high-bandwidth ferromagnetic resonance spectroscopy with a coherent, extreme ultraviolet (EUV) source
We developed and applied a tabletop, ultrafast, high-harmonic generation (HHG) source to measure the element-specific ferromagnetic resonance (FMR) in ultra-thin magnetic alloys and multilayers on an opaque Si substrate. We demonstrate a continuous wave bandwidth of 62 GHz, with promise to extend to 100 GHz or higher. ...
2402.00783v1
2024-02-09
Maximizing Consistent Force Output for Shape Memory Alloy Artificial Muscles in Soft Robots
Soft robots have immense potential given their inherent safety and adaptability, but challenges in soft actuator forces and design constraints have limited scaling up soft robots to larger sizes. Electrothermal shape memory alloy (SMA) artificial muscles have the potential to create these large forces and high displace...
2402.06201v1
2024-02-23
Ubiquitous short-range order in multi-principal element alloys
Recent research in multi-principal element alloys (MPEAs) has increasingly focused on the exploration and exploitation of short-range order (SRO) to enhance material performance. However, the understanding of SRO formation and the precise tuning of it within MPEAs remains poorly understood, limiting the comprehension o...
2402.15305v1
2024-02-27
Improved understanding of the growth of blocky alpha in welded Zircaloy-4
Zirconium alloys are widely used in nuclear reactors as fuel cladding materials. Fuel cladding is used to contain the nuclear fuel and cladding tubes are typically sealed using welds. Welding of zirconium alloys can result in changes in the local microstructure, with the potential to grow so called 'blocky {\alpha}' gr...
2402.17093v1
2024-03-12
Grain growth competition and formation of grain boundaries during solidification of hcp alloys
Grain growth competition during directional solidification of a polycrystal with hexagonal (hcp) symmetry (Mg-1wt%Gd alloy) is studied by phase-field modeling, exploring the effect of the temperature gradient G on the resulting grain boundary (GB) orientation selection. Results show that selection mechanisms and scalin...
2403.07416v2
2024-03-17
Microstructural and Mechanistic Insights into the Tension-Compression Asymmetry of Rapidly Solidified Fe-Cr Alloys: A Phase Field and Strain Gradient Plasticity Study
Rapid solidification in Additively Manufactured (AM) metallic materials results in the development of significant microscale internal stresses, which are attributed to the printing induced dislocation substructures. The resulting backstress due to the Geometrically Necessary Dislocations (GNDs) is responsible for the o...
2403.11080v1
2024-03-27
Deciphering Chemical Ordering in High Entropy Materials: A Machine Learning-Accelerated High-throughput Cluster Expansion Approach
The Cluster Expansion (CE) Method encounters significant computational challenges in multicomponent systems due to the computational expense of generating training data through density functional theory (DFT) calculations. This work aims to refine the cluster and structure selection processes to mitigate these challeng...
2403.18298v1
2024-03-30
Gradient bandgap enables >13% efficiency sulfide Kesterite solar cells with open-circuit voltage over 800 mV
Sulfide Kesterite Cu2ZnSnS4 (CZTS), a nontoxic and low-cost photovoltaic material, has always being facing severe charge recombination and poor carrier transport, resulting in the cell efficiency record stagnating around 11% for years. Gradient bandgap is a promising approach to relieve these issues, however, has not b...
2404.00291v1
2015-10-12
Room-temperature spin-orbit torque in NiMnSb
Materials that crystalize in diamond-related lattices, with Si and GaAs as their prime examples, are at the foundation of modern electronics. Simultaneoulsy, the two atomic sites in the unit cell of these crystals form inversion partners which gives rise to relativistic non-equilibrium spin phenomena highly relevant fo...
1510.03356v1
2016-11-14
Phase diagram of electronic systems with quadratic Fermi nodes in $2<d<4$: $2+ε$ expansion, $4-ε$ expansion, and functional renormalization group
Several materials in the regime of strong spin-orbit interaction such as HgTe, the pyrochlore iridate Pr$_2$Ir$_2$O$_7$, and the half-Heusler compound LaPtBi, as well as various systems related to these three prototype materials, are believed to host a quadratic band touching point at the Fermi level. Recently, it has ...
1611.04594v2
2017-07-12
Superconductivity in three-dimensional spin-orbit coupled semimetals
Motivated by the experimental detection of superconductivity in the low-carrier density half-Heusler compound YPtBi, we study the pairing instabilities of three-dimensional strongly spin-orbit coupled semimetals with a quadratic band touching point. In these semimetals the electronic structure at the Fermi energy is de...
1707.03831v2
2018-01-22
Effect of density functionals on the vibrational and thermodynamic properties of Fe$_{2}$VAl and Fe$_{2}$TiSn compounds
First-principles phonon calculations along with Kohn-Sham density functional theory (DFT) is an essential tool to study the lattice dynamics, thermodynamical properties and phase-transitions of materials. The two full-Heusler compounds Fe$_{2}$VAl and Fe$_{2}$TiSn are studied for lattice vibration dependent properties ...
1801.06980v2
2018-11-29
Interacting spin-3/2 fermions in a Luttinger semimetal: Competing phases and their selection in the global phase diagram
We compute the effects of electronic interactions on gapless spin-3/2 excitations that in a noninteracting system emerge at a bi-quadratic touching of Kramers degenerate valence and conduction bands, known as Luttinger semimetal. This model can describe the low-energy physics of HgTe, gray-Sn, 227 pyrochlore iridates a...
1811.12415v2
2017-04-05
Structure, site-specific magnetism and magneto-transport properties of epitaxial D0$_{22}$ Mn$_2$Fe$_x$Ga thin films
Ferrimagnetic Mn$_2$Fe$_x$Ga $(0.26 \leq x \leq 1.12)$ thin films have been characterised by X-ray diffraction, SQUID magnetometry, X-ray absorption spectroscopy, X-ray magnetic circular dichroism and M\"{o}ssbauer spectroscopy with the aim of determining the structure and site-specific magnetism of this tetragonal, D0...
1704.01326v1
2016-03-10
Beyond Triplet: Unconventional Superconductivity in a Spin-3/2 Topological Semimetal
In all known fermionic superfluids, Cooper pairs are composed of spin-1/2 quasi-particles that pair to form either spin-singlet or spin-triplet bound states. The "spin" of a Bloch electron, however, is fixed by the symmetries of the crystal and the atomic orbitals from which it is derived, and in some cases can behave ...
1603.03375v4
2020-09-02
New highly-anisotropic Rh-based Heusler compound for magnetic recording
The development of high-density magnetic recording media is limited by the superparamagnetism in very small ferromagnetic crystals. Hard magnetic materials with strong perpendicular anisotropy offer stability and high recording density. To overcome the difficulty of writing media with a large coercivity, heat assisted ...
2009.01034v1
2020-12-10
Magnetic order and magneto-transport in half-metallic ferrimagnetic Mn$_y$Ru$_x$Ga thin films
The ruthenium content of half-metallic Mn$_2$Ru$_x$Ga thin films, with a biaxially-strained inverse Heusler structure, controls the ferrimagnetism that determines their magnetic and electronic properties. An extensive study of Mn$_y$Ru$_x$Ga films on MgO (100) substrates with $1.8 \leq y \leq 2.6$ and $x = 0.5$, 0.7 or...
2012.05736v5
2021-06-22
Superconductivity in spin-$3/2$ systems: symmetry classification, odd-frequency pairs, and Bogoliubov Fermi surfaces
The possible symmetries of the superconducting pair amplitude is a consequence of the fermionic nature of the Cooper pairs. For spin-$1/2$ systems this leads to the $\mathcal{SPOT}=-1$ classification of superconductivity, where $\mathcal{S}$, $\mathcal{P}$, $\mathcal{O}$, and $\mathcal{T}$ refer to the exchange operato...
2106.11983v2
2021-10-26
Spin- and time-resolved photoelectron spectroscopy and diffraction studies using time-of-flight momentum microscopes
Momentum microscopy (MM) is a novel way of performing angular-resolved photoelectron spectroscopy (ARPES). Combined with time-of-flight (ToF) energy recording, its high degree of parallelization is advantageous for photon-hungry experiments like ARPES at X-ray energies and spin-resolved ARPES. This article introduces i...
2110.13832v2
2021-11-03
Antiskyrmions and their electrical footprint in crystalline mesoscale structures of Mn$_{1.4}$PtSn
Skyrmionic materials hold the potential for future information technologies, such as racetrack memories. Key to that advancement are systems that exhibit high tunability and scalability, with stored information being easy to read and write by means of all-electrical techniques. Topological magnetic excitations such as ...
2111.02494v3
2022-07-12
First-principles study of optoelectronic and thermoelectronic properties of the ScAgC half-Heusler compound
This work presents a theoretical study regarding photovoltaic (PV) & thermoelectric (TE) applications of ScAgC. The electronic, optical and thermoelectric properties are investigated using DFT and semi-classical Boltzmann transport theory. DFT calculates a direct band-gap of $\sim$$0.47$ eV, while $G_{0}W_{0}$ method e...
2207.05661v2
2022-10-09
High-performance non-Fermi-liquid metallic thermoelectric materials
Searching for high-performance thermoelectric (TE) materials in the paradigm of narrow-bandgap semiconductors has lasted for nearly 70 years and is obviously hampered by a bottleneck of research now. Here we report on the discovery of a few metallic compounds, TiFexCu2x-1Sb and TiFe1.33Sb, showing the thermopower excee...
2210.04201v1
2023-01-03
Surprisingly large anomalous Hall effect and giant negative magnetoresistance in half-topological semimetals
Large intrinsic anomalous Hall effect (AHE) due to the Berry curvature in magnetic topological semimetals is attracting enormous interest due to its fundamental importance and technological relevance. Mechanisms resulting in large intrinsic AHE include diverging Berry curvature in Weyl semimetals, anticrossing nodal ri...
2301.01074v1
2023-09-14
Composition and Structure Based GGA Bandgap Prediction Using Machine Learning Approach
This study focuses on developing precise machine learning (ML) regression models for predicting energy bandgap values based on chemical compositions and crystal structures. The primary aim is to match the accuracy of predictions derived from GGA-PBE calculations and validate them through density functional theory (DFT)...
2309.07424v1
2024-03-19
PH-NODE: A DFPT and finite displacement supercell based python code for searching nodes in topological phononic materials
Exploring the topological physics of phonons is fundamentally important for understanding various practical applications. Here, we present a density-functional perturbation theory and finite displacement supercell based Python 3 software package called PH-NODE for efficiently computing phonon nodes present in real mate...
2403.12643v1
2001-12-30
Study of the Ce(Rh$_{1-x}$Pd$_x$)$_2$Si$_2$ alloy: evidence for itinerant character of the magnetic order in CeRh$_2$Si$_2$
We present electrical resistivity and specific heat measurements of alloys on the Rh rich side of the phase diagram of the Ce(Rh$_{1-x}$Pd$_x$)$_2$Si$_2$ system and compare the results with those obtained at intermediate and low Rh concentrations. The analysis of the x-evolution of the entropy and the scaling behaviour...
0112495v1