We report the polycrystalline synthesis, crystal structure and superconducting properties of a new noncentrosymmetric compound ${\mathrm{Sc}}_6{\mathrm{RuSb}}_2$, which crystallizes in a hexagonal ${\mathrm{Fe}}_2\mathrm{P}$-type derived structure (space group $P\text{−}62m$, No. 189). Electrical resistivity, magnetic susceptibility, and specific heat measurements reveal a superconducting critical temperature $T_{\mathrm{c}}=3.95\mathrm{K}$ and an upper critical field ${\mu }_0{H}_{\mathrm{c}2}\left(0\right)=5.2\mathrm{T}$. The temperature dependence of the upper critical field suggests possible multiband superconducting behavior. The specific heat jump $\mathrm{\Delta }{C}_{\mathrm{e}}/{\gamma }_{\mathrm{n}}{\mathit{T}}_{\mathrm{c}}=1.65$ and the coupling strength $2{\mathrm{\Delta }}_0/k_{\mathrm{B}}{T}_{\mathrm{c}}=3.76$ both exceed the weak-coupling BCS limit, indicating moderate electron-phonon coupling. Compared to the structurally analogous compound ${\mathrm{Sc}}_6{\mathrm{RuTe}}_2$ ($T_{\text{c}}^{\text{zero}}\sim$ 1.9 K), the $T_{\mathrm{c}}$ of ${\mathrm{Sc}}_6{\mathrm{RuSb}}_2$ is nearly doubled. First-principles calculations show that substituting Sb for Te reduces the valence electron count, shifting the Fermi level from a density-of-states (DOS) valley toward a nearby DOS peak, which enhances the DOS at the Fermi level and accounts for the increased $T_{\mathrm{c}}$.

We report a solid-phase epitaxial approach that overcomes the difficulty of synthesizing ${\mathrm{V}}_2{\mathrm{O}}_3$ films with bulk-like electrical properties. The synthesis method consists of highly reproducible processes in which amorphous precursor $\mathrm{V}{\mathrm{O}}_x$ films are deposited on $\alpha \text{−}{\mathrm{Al}}_2{\mathrm{O}}_3$ substrates at room temperature and subsequently annealed $\mathit{ex}$ situ in an ${\mathrm{H}}_2$ atmosphere. By optimizing the annealing temperature to $600–800{}^{\circ }\mathrm{C}$, the ${\mathrm{V}}_2{\mathrm{O}}_3$ films exhibited a clear metal–insulator transition (MIT) at approximately 160 K with a resistivity jump of nearly six orders of magnitude. The MIT characteristics are comparable to the MIT properties of stoichiometric bulk ${\mathrm{V}}_2{\mathrm{O}}_3$ and high-quality films grown directly using conventional physical vapor deposition methods. X-ray diffraction measurements confirmed epitaxial growth of the films on isostructural $\alpha \text{−}{\mathrm{Al}}_2{\mathrm{O}}_3$ substrates with $a$-, $c$-, and $m$-plane orientations. Our study establishes a reproducible route for synthesizing ${\mathrm{V}}_2{\mathrm{O}}_3$ films with robust MIT characteristics for Mott-transition-based electronic devices.

We present a first-principles investigation of defect energetics and vacancy-mediated diffusion in pristine and Zr-doped CoCrFeNi high-entropy alloys using density functional theory and climbing-image nudged elastic band calculations. The Zr substitution stabilizes the fcc solid solution, introducing pronounced local chemical disorder and electronic inhomogeneity. Analysis of the electronic density of states reveals significant broadening and redistribution of $d$ states near the Fermi level upon Zr addition, indicating modified hybridization with the transition-metal matrix. These electronic changes lead to a substantial increase in intrinsic stacking-fault energy from $-67.74\pm 5.38\mathrm{mJ}{\mathrm{m}}^{-2}$ to $93.13\pm 12.72\mathrm{mJ}{\mathrm{m}}^{-2}$, signaling a shift in deformation mechanisms. Bader charge analysis reveals that Zr acts as the dominant electron donor in the system, transferring approximately $+0.90e$ to the surrounding transition-metal matrix, substantially greater than the maximum charge donation of Cr ($\sim +0.60e$) in the undoped alloy. Vacancy formation energies and migration barriers exhibit strong configurational variability, reflecting the heterogeneous local bonding environment. In the presence of Zr, vacancy formation is locally facilitated, accompanied by strong solute-vacancy binding that promotes vacancy trapping. Migration pathways evolve from relatively symmetric, single-stage profiles in the pristine alloy to broadened, asymmetric, and multistage energy landscapes in the Zr-containing system. Zr itself exhibits the highest mean migration barrier ($1.315\pm 0.507\mathrm{eV}$) and an anomalous double-peaked migration profile attributed to its weak $4d-3d$ hybridization. Overall, these results establish a direct connection between solute-induced modifications in electronic structure and the resulting changes in the energetics of the defect and diffusion behavior, providing a unified framework for tailoring defect properties in high-entropy alloys through electronic and chemical design.

$\text{A}{\text{l}}_x\text{G}{\text{a}}_{1-x}\text{N}/\text{GaN}$ superlattices are widely used in GaN-based power electronics and optoelectronics for regulation of electronic and optoelectronic properties. However, thermal transport in these superlattices, which is critical for device performance and reliability, remains poorly understood. In this work, we have systematically investigated the effect of alloy on thermal transport in $\text{A}{\text{l}}_x\text{G}{\text{a}}_{1-x}\text{N}/\text{GaN}$ superlattices using homogeneous nonequilibrium molecular dynamics based on machine-learning interatomic potentials. A nonmonotonic interface-density dependence of thermal conductivity κ is observed in both pristine AlN/GaN and $\text{A}{\text{l}}_x\text{G}{\text{a}}_{1-x}\text{N}/\text{GaN}$ superlattices, with a global minimum at an interface density of about $0.2\mathrm{n}{\mathrm{m}}^{-1}$. Unlike in AlN/GaN superlattices, the κ contributed by coherent phonons is largely suppressed in $\text{A}{\text{l}}_x\text{G}{\text{a}}_{1-x}\text{N}/\text{GaN}$ superlattices because alloy disorder disrupts the formation of coherent Bloch phonons by reducing interfacial modes and introducing scattering centers. As a result, the κ of $\text{A}{\text{l}}_x\text{G}{\text{a}}_{1-x}\text{N}/\text{GaN}$ superlattices at high interface densities approaches the values of the corresponding alloys with the same average composition, where thermal transport is dominated by incoherent phonons. This work provides deep insights into the strong effect of alloy on thermal transport in $\text{A}{\text{l}}_x\text{G}{\text{a}}_{1-x}\text{N}/\text{GaN}$ superlattices, and will benefit the regulation of thermal properties by superlattice design for applications in power electronics and optoelectronics.

Inorganic halide perovskites are important optoelectronic materials known to present anharmonicity and local structural disorder. While the influence of local disorder on bulk properties has received growing attention, its impact on surface properties remains unexplored. In this work, we use density functional theory (DFT) calculations to systematically investigate the effect of local disorder on the surface properties of cubic $\mathrm{Cs}B{X}_3$ perovskites ($B$ = Sn, Pb; $X$ = I, Br, Cl). We find that introducing local disorder through polymorphous configurations lowers the surface energy, making disordered surfaces more thermodynamically favorable than their high-symmetry counterparts. Local disorder also induces a downward shift in the valence band maximum (VBM) due to the elongation of $B-X$ bonds, the tilt of ${BX}_6$ octahedra, as well as a modification of surface dipoles. We employed semilocal functionals along with DFT-1/2 quasiparticle corrections to determine the absolute band positions. Our results reveal that semilocal functionals alone fail to capture the trends in the VBM across different halide compositions, whereas the inclusion of DFT-1/2 corrections successfully restores the experimentally observed trends. Furthermore, calculations based on polymorphous structures yield VBM values in much closer agreement with experimental measurements compared to those obtained from monomorphous archetypal ordered structures. This demonstrates that explicitly accounting for the polymorphous nature of the material and employing DFT-1/2 corrections lead to a more realistic description of surface electronic properties than assuming an idealized monomorphous framework and relying on semilocal DFT. These findings reveal local disorder as a key design parameter for perovskite surfaces, opening new opportunities for tuning interfacial energetics and improving device performance.

Calvin et al. [Proc. Natl. Acad. Sci. USA 121, e2307633121 (2024)] recently reported a result that sounds thermodynamically forbidden: semiconductor quantum dots with negative surface energy. If creating surface area lowers a system's free energy, why do these materials not spontaneously subdivide into oblivion? As Calvin et al. qualitatively recognized, this paradox vanishes because a ligand-capped nanocrystal is not a pristine solid-vacuum boundary, but a chemically open system where favorable ligand adsorption can drive the scalar surface excess negative. In this work, we formalize this physical distinction by extending the theory of continuum surface mechanics to account for chemically open, ligand-decorated surfaces. Our framework decouples the scalar calorimetric excess from its mechanical derivatives, illustrating that an apparent negative surface energy implies neither negative surface stress nor mechanical instability. Furthermore, this open-system formulation predicts fundamental chemomechanical phenomena: ligand relaxation softens tangent surface moduli, and adsorption-stress Maxwell relations explicitly link lattice strain to ligand coverage. Applying this theory, we demonstrate that nanostructure behavior is governed by the derivatives of the open-system interfacial free energy and finite-size corrections rather than the scalar energy alone. Open-system residual stress dictates lattice strain; favorable chemical interfacial energy drives core/shell wetting by overpowering positive elastic mismatch; and geometric regularizations, such as curvature, thermodynamically arrest runaway subdivision.

Barium titanate–based perovskites are important candidates for lead-free dielectric and electromechanical technologies. In Zr-substituted ${\mathrm{BaTiO}}_3$, functional behavior is usually discussed in terms of the average Zr concentration, while the influence of dopant spatial distribution beyond average concentration is less understood and difficult to explore systematically. Here we present an accelerated materials-design workflow that links controlled dopant distributions to full field-driven response curves. We generate a broad set of Zr distributions spanning a continuum of nanoscale arrangements, with layers, rods, dots, and lamellae serving as representative end-member motifs, and encode each configuration using a compact, parametrized descriptor model. Effective-Hamiltonian molecular dynamics is used to compute polarization–electric-field and strain–field hysteresis loops and we train a conditional autoencoder surrogate to predict complete loops directly from the distribution parameters. This surrogate enables rapid screening and dense, property-selective design maps at scales that are not feasible with direct simulations alone and it supports targeted follow-up simulations in regions of interest. Using the predicted loop database, we screen the distribution space for multiple functional targets, including energy-storage performance, electromechanical response, and switching behavior, and identify the corresponding dopant distribution motif families. The resulting design maps show that dopant distribution is an independent tuning parameter that can strongly affect hysteresis behavior and loop-derived figures of merit: layerlike motifs, vertical lamellae, and nanoplatelike inclusions emerge in different performance regimes. More generally, predicting full response curves enables screening of other loop-derived targets and multiobjective design in substituted ferroelectrics.

Transverse thermoelectric generation based on the anomalous Nernst effect (ANE) in topological magnets attracted attention because of the potential applications in novel thermoelectric devices. However, realizing engineering applications requires elucidating the enhancement mechanism of the ANE and establishing material design guidelines. Here, we demonstrate via first-principles calculations that strains engineering, a promising approach that tunes electronic structures and enhances material functionality through strain loading, maximizes the ANE in the magnetic Weyl semimetal ${\mathrm{Co}}_3{\mathrm{Sn}}_2{\mathrm{S}}_2$. Tensile strain enhances the anomalous Nernst conductivity by approximately threefold relative to the unstrained state. We find that strain-tunable nodal lines reduce their energy dispersion and induce large Berry curvature, providing the key mechanism for enhancing the anomalous Nernst conductivity. A detailed analysis of band structure and its chemical bonding clarifies the relationship between the applied strain, strain-tunable nodal lines, and enhancement of the anomalous Nernst conductivity. These results directly connect theoretical predictions of the ANE enhancement to strain as an engineering parameter, providing material design guidelines for superior thermoelectric devices.

Perpendicularly magnetized multilayers (MLs) with low magnetic damping and highly periodic stripe domains are promising materials for energy-efficient spintronic and magnonic devices. Here, we investigate the structure, together with the static and dynamic magnetic properties of a polycrystalline sputter-deposited ${[\mathrm{CoFeB}\left(0.3\mathrm{nm}\right)/\mathrm{Ni}\left(0.6\mathrm{nm}\right)]}_{50}$ ML and compare it to a ${[\mathrm{Co}\left(0.3\mathrm{nm}\right)/\mathrm{Ni}\left(0.6\mathrm{nm}\right)]}_{50}$ reference stack. Scanning transmission electron microscopy, supplemented by atomic force microscopy, reveals that using a CoFeB/Ni ML yields a more cohesive and denser grain microstructure than in the Co/Ni ML. Our structural results are corroborated by reciprocal-space x-ray reflectivity and x-ray diffraction, further indicating a smoother CoFeB/Ni ML with weakened crystallographic texture and reduced crystalline coherence lengths compared to the Co/Ni ML, while preserving the overall $\mathrm{fcc}\left(111\right)$ growth induced by the Pt seed layer. Vibrating sample magnetometry shows that the CoFeB/Ni ML exhibits weak perpendicular magnetic anisotropy (PMA), resulting in near-zero-remanence isotropic labyrinth stripe domains following out-of-plane saturation and parallel stripe domains after in-plane saturation, consistent with the absence of strong pinning sites. In contrast, the Co/Ni ML exhibits stronger PMA and more pinning-mediated, disordered domain patterns due to its more inhomogeneous microstructure. Field-dependent magnetic force microscopy demonstrates an evolution from labyrinth stripe to dense bubble domain states in the CoFeB/Ni ML, accompanied by a reduction in microscopic return-point memory of the remanent state. Broadband ferromagnetic resonance measurements further disclose a $25\%$ reduced Gilbert damping parameter $\alpha$ in the CoFeB/Ni ($\alpha =0.0147$) compared to the Co/Ni ML ($\alpha =0.0193$), along with a massive 370-fold reduction of the inhomogeneous linewidth broadening. The combined structural, magnetic, and dynamic results indicate that using CoFeB suppresses microstructure-induced magnetic inhomogeneities while staying in the PMA regime. These findings identify CoFeB/Ni MLs as a promising platform for perpendicular spintronic devices, combining low magnetic damping, which is beneficial for coherent magnetization dynamics and long-range magnonic signal propagation, with well-defined domain states.

Understanding magnetization dynamics is essential for advancing the applicability of future magnetic devices. Specifically, materials with low magnetization damping are crucial for minimizing energy loss, enhancing sensitivity, and enabling long-distance spin-wave propagation in spintronic and magnonic systems. Here, we determine the effective Gilbert damping of ferromagnetic and insulating EuS thin films by means of ferromagnetic resonance spectroscopy in the frequency range from 7 to 25 GHz and temperatures between 2 K and 30 K. We find that the damping of EuS thin films between 20 and 60 nm decreases as the temperature is lowered and can be as low as ${10}^{-3}$ even in polycrystalline films. We measure the lowest damping in 40-nm-thick EuS films, consistent with the presence of structural and chemical defects at the substrate/film interface. At the lowest measured temperature, we find the damping comparable with the case of yttrium iron garnet and permalloy films in the same temperature regime.

The compound ${\mathrm{SrNi}}_2{\mathrm{P}}_2$ can exhibit multiple crystal structures with no P-P pairs bonded (uncollapsed tetragonal, or ucT, state), with one-third of the P-P pairs bonded (one-third collapsed orthorhombic, or tcO, state), or with all P-P pairs bonded (collapsed tetragonal, or cT, state) across the Sr layers. The system can be tuned into its different states by changing temperature, mechanical stress, or chemical composition. Changes in bonding may manifest in changes of macroscopic properties of the material, such as its shape, electrical conductivity, or magnetism. In this work, we show that ${\mathrm{SrNi}}_2{\mathrm{P}}_2$ can be tuned among the three states by changing Cu substitution and temperature. We present temperature-dependent resistance and single-crystal x-ray diffraction results in $\mathrm{Sr}{\left({\mathrm{Ni}}_{1-x}{\mathrm{Cu}}_x\right)}_2{\mathrm{P}}_2$ single-crystals that show that Cu substitution favors the P-P bonding, stabilizing the cT state at ambient pressure. We construct a $T-x$ phase diagram that shows how all of these transition temperatures increase with increasing Cu fraction, $x$. The transition between the tcO state and the cT state exhibits a very large thermal hysteresis, which can be tuned to temperatures close to room temperature. In particular, the properties of Sr(${\mathrm{Ni}}_{0.963}{\mathrm{Cu}}_{0.037}{)}_2{\mathrm{P}}_2$ may make it suitable for applications as a shape-memory material at room temperature.

This study introduces a novel two-dimensional inorganic graphenylenelike monolayer, scandium nitride (IGP-ScN), and examines its stability and functional properties using density functional theory (DFT) simulations. Phonon dispersion analysis and ab initio molecular dynamics in the NVT ensemble (300–900 K) confirm both dynamical and thermal robustness. At the PBE level, electronic structure calculations indicate an indirect band gap at $M\to \mathrm{\Gamma }$. The Bethe-Salpeter equation solution reveals an indirect excitonic ground state and an optical gap at 1.96 eV, indicating a large exciton binding energy (646 meV) and a pronounced excitonic red shift. The monolayer satisfies the Born-Huang stability criteria and demonstrates an essentially isotropic in-plane elastic response, with a Young's modulus of approximately 52 N/m, a shear modulus of approximately 17 N/m, and a Poisson's ratio of approximately 0.51. The lattice thermal conductivity is low, ranging from 0.09 W/(m K) at 300 K to 0.03 W/(m K) at 900 K. Although the undoped structure has low figure-of-merit (zT) values, doping at elevated temperatures can improve performance, with electron doping more effective than hole doping. Power conversion efficiency (PCE) results show Shockley-Queisser limit efficiencies of $10.58\%$ at the independent particle approximation level and $23.19\%$ at the Bethe-Salpeter level, with the latter enhanced by the excitonic redshift, which reduces the optical band gap from 2.42 to 1.96 eV. These findings may encourage further investigation of new III–V semiconductors and novel inorganic lattices by both experimental and theoretical researchers.

We report the magnetic properties of a ${\mathrm{Yb}}^{3+}$-based hyperkagome compound ${\mathrm{Yb}}_3{\mathrm{Ga}}_2{\mathrm{Al}}_3{\mathrm{O}}_{12}$ characterized via different experimental techniques and complemented by crystal electric field (CEF) calculations. The magnetic measurements suggest the absence of magnetic long-range order down to 0.1 K, and the ground state is a Kramers doublet with an effective spin $J_{\mathrm{eff}}=1/2$. A small Curie–Weiss temperature and magnetic scaling analysis suggest weak interaction among the magnetic $J_{\mathrm{eff}}=1/2$ entities. The temperature-dependent magnetic susceptibility and magnetic heat capacity could be described by a two-level Schottky function arising from the Zeeman splitting of the ground-state Kramers doublet. The CEF parameters are calculated using the point charge model. After diagonalizing the CEF Hamiltonian, we obtained the CEF energy eigenvalues and the corresponding wave functions. The simulated magnetization and heat capacity using these CEF parameters nicely reproduce our experimental data. The large separation between the ground state and the first excited state doublets in the calculated CEF scheme further supports a $J_{\mathrm{eff}}=1/2$ state at lower temperatures.

In this study, we present a comprehensive analysis of the Raman-active phonon modes in orthorhombic ${\mathrm{LaInO}}_3$ based on a combination of polarization-angle resolved Raman spectroscopy and density functional theory calculations. By using backscattering from multiple crystallographic surface orientations and employing a full symmetry analysis, we identify and assign most of the Raman-active $\mathrm{\Gamma }$-point phonons to their irreducible representations of the $D_{2h}$ point group. A multidimensional hyperspectral fitting procedure allows us to extract the relative Raman tensor elements from the angular dependence of the scattering intensities, even for strongly overlapping modes. First-principles calculations yield the phonon dispersion along high-symmetry directions, the phonon densities of states, atomic displacement patterns, and Raman tensor elements, which are found to be in good agreement with the experiment.

High pressure provides an effective route to activate molecular nitrogen and access nitrogen-rich compounds with unusual bonding motifs. Here we investigate the Eu–N system under pressure by combining attention-coupled neural network (ACNN)-assisted structure searches, first-principles calculations, and laser-heated diamond-anvil-cell experiments. Convex-hull analyses reveal a rich Eu–N phase landscape across 0–100 GPa, including nine thermodynamically stable $\mathrm{Eu}{\mathrm{N}}_x$ phases with nitrogen motifs ranging from isolated or dimeric units to cyclic, chainlike, layered, and molecularly confined configurations. Guided by these predictions, we synthesized a previously unreported $R\overline{3}m {\mathrm{EuN}}_{12}$ phase at 45–56 GPa, representing an experimental realization of this nitrogen-rich europium nitride stoichiometry. ${\mathrm{EuN}}_{12}$ contains dense lattice-confined ${\mathrm{N}}_2$-like dumbbells with a short N–N distance of 1.133 Å at 50 GPa and remains traceable upon decompression to 5 GPa, indicating the robustness of its confined molecular nitrogen units. Electronic-structure and bonding analyses suggest that localized Eu $4f$ states act as a valence-buffering reservoir, moderating Eu-to-nitrogen charge transfer and limiting occupation of ${\mathrm{N}}_2$-derived antibonding states. These results establish the Eu–N system as a rare-earth platform for nitrogen-rich compounds and reveal how pressure, localized $4f$ electrons, and nitrogen-motif evolution cooperate to stabilize high-pressure nitrides with confined molecular nitrogen units.

Control of structural domains in epitaxial thin films of functional materials is a fundamental technique to utilize their intrinsic physical and chemical properties in solid-state devices. In this study, we report on suppression of twisted-domain formation in thin-film growth of polar magnetic semiconductor $\mathrm{AgCrS}{\mathrm{e}}_2$ using pulsed-laser deposition. In exploring simultaneously optimized growth temperature and Ag/Cr composition ratio of supply, we find the critical growth temperature ($T_{\mathrm{sub}}$) for obtaining single ${60}^{\circ }$ domain in $c$-axis-oriented $\mathrm{AgCrS}{\mathrm{e}}_2$ thin film on a lattice-matched (111) plane of the yttria-stabilized zirconia substrate. At temperatures below and above the critical $T_{\mathrm{sub}}$, metastable $0^{\circ }$ domain in addition to the ${60}^{\circ }$ domain emerges, indicating delicate energy balance of thermodynamic stability for obtaining the single-domain structure. On the other hand, surface structural analysis using time-of-flight low-energy atom scattering spectroscopy reveals the presence of two polar orientations along +$Z$ and −$Z$ directions. These findings provide valuable insights into the thin-film growth mechanisms for a family of two-dimensional compounds with rhombohedral lattices.