Magnetic materials that combine strong spin-orbit coupling with ferromagnetism enable interconversion between charge and spin currents as well as stabilization of exotic spin textures, properties that are critical for advancing next-generation spintronic technologies. The metallic delafossite ${\mathrm{PdCoO}}_2$ is a highly conductive, nonmagnetic oxide that resides near a magnetic instability, making it a unique and promising monolithic platform for spin phenomena. Here, we investigate how helium implantation drives ${\mathrm{PdCoO}}_2$ into a magnetic state. Through depth-resolved low-energy muon spin relaxation (LE-μSR) measurements, ion implantation simulations, and first-principles calculations, the defects responsible for the emergent magnetism are identified. While oxygen Frenkel pairs, palladium Frenkel pairs, and interstitial helium contribute weakly, cobalt Frenkel pairs play the dominant role in generating magnetism. In addition, postimplantation annealing reveals distinct thermal windows for defect recombination, confirming the elemental specificity of cation-related defects. These findings establish defect engineering via ion implantation as a powerful route to controllably induce magnetism in ${\mathrm{PdCoO}}_2$. The combination of strong spin-orbit coupling, selectively tunable magnetism, and ultrahigh conductivity positions helium-implanted ${\mathrm{PdCoO}}_2$ as a unique platform for monolithic spintronic device integration, with implications for low-power magnetic memory and unconventional logic applications.

With the rapid development of integrated electro-optic and nonlinear optical devices based on lithium niobate (${\mathrm{LiNbO}}_3$, LN), thermal management is becoming a critical area of focus. However, experimental measurement of thermal transport in stoichiometric ${\mathrm{LiNbO}}_3$ (sLN) remains scarce, and the intrinsic microscopic mechanisms remain to be established. Here, we combine the laser pump-probe technique of frequency-domain thermoreflectance (FDTR) with state-of-the-art machine-learned atomistic simulations to comprehensively investigate thermal transport in sLN. The measured and simulated room-temperature thermal conductivity ($\kappa$) values of sLN agree well, which are orders of magnitude lower than those of many classic and emerging semiconductors such as silicon. Furthermore, the temperature-dependent $\kappa$ exhibits $T^{-\alpha }$ scaling with $\alpha$ near unity, suggesting that thermal transport is dominated by intrinsic phonon-phonon scattering. By comparing sLN with cubic boron arsenide (cBAs) which serves as an ultrahigh-$\kappa$ benchmark, we reveal that harmonic properties are not responsible for the low $\kappa$ of sLN, which feature phonon heat capacity and group velocities that are either higher than or comparable with those in cBAs. Instead, the low $\kappa$ originates from substantially stronger anharmonicity and larger scattering phase space. These two factors collectively suppress phonon lifetimes by 1–2 orders of magnitude, leading to a maximum phonon mean free path of approximately 140 nm. As a result, notable size effects emerge in thin-film sLN below 1 µm, with $\kappa$ dropping to half the bulk value at 10 nm. Altogether, our findings establish a fundamental understanding of thermal transport in sLN and provide atomistic insights for thermal management in advanced lithium niobate technologies.

Lithium niobate (${\mathrm{LiNbO}}_3$) is a key anisotropic material for midinfrared photonics, nonlinear optics, and acousto-optic applications, where accurate dielectric function (DF) models are required for optical simulations under arbitrary crystallographic orientations. In this work, an anisotropic DF model for commercial X-, ${\text{Y-128}}^{\circ }$, and Z-cut ${\mathrm{LiNbO}}_3$ substrates is developed in the infrared (IR) spectral range using a factorized transverse optical and longitudinal optical (TO-LO) formalism. The model is obtained through spectroscopic ellipsometry (SE) supported by polarized Raman spectroscopy and IR reflectance measurements. These complementary techniques enable the identification and cross-validation of phonon modes associated with the in-plane $E\left(x\right)$ and out-of-plane $A_1\left(z\right)$ components of the dielectric tensor (DT). A single parametrized DT consistently reproduces the optical response of all analyzed crystal cuts through appropriate Euler-angle rotations, including different azimuthal configurations that exhibit distinct birefringent responses. The proposed approach provides a Kramers-Kronig consistent description of the dielectric response through a physically constrained parametrization, reducing parameter correlations during optical modeling. The resulting DF is presented in analytical form over the $230-1200{\mathrm{cm}}^{-1}$ spectral range and is directly applicable to integrated photonics, acousto-optic, and nonlinear optical device simulations in the IR.

Structural design has been increasingly exploited as an effective strategy for broadband microwave absorption, enabling tailored electromagnetic responses without modifying intrinsic material compositions. In this work, a structure-mediated magnetic composite absorber is proposed by introducing a cruciform unit cell with a four-lobed central aperture, which allows parameter modulation of the frequency-dependent effective permittivity and permeability through geometry-induced electric and magnetic field localization, thereby achieving broadband impedance matching and efficient dielectric-magnetic loss synergy. Both simulations and experiments demonstrate that the proposed absorber, with a total thickness of 4 mm, exhibits an effective absorption bandwidth of 13.0 GHz (4.5–17.5 GHz, reflection loss <$-10\mathrm{dB}$), covering the C, X, and Ku bands. In addition, the design exhibits polarization insensitivity and stable performance under a moderate oblique incidence of up to ${30}^{\circ }$. This work establishes a single-layer, composition-preserving strategy in which geometry-induced electric and magnetic responses are jointly engineered, extending broadband magnetic-composite absorber design beyond conventional material reformulation and multilayer stacking.

Quasi-2D ${\mathrm{Bi}}_2{\mathrm{O}}_2\mathrm{Se}$ is part of an intensive materials research effort aimed at finding new semiconductors that outperform silicon-based electronics in terms of speed and power consumption. This material exhibits exceptionally high carrier mobility at low temperatures but mediocre mobility at 300 K. Its high mobility is generally associated with its high permittivity (${\varepsilon }_r\approx 500$), which is also associated with metallicity persisting down to very low carrier concentrations. This material exhibits a counterintuitive increase in carrier mobility as the concentration increases. The connection between both low carrier concentration and mobility in Se-rich conditions, and both high carrier concentration and mobility in Se-poor conditions suggests that the increase is related to native defects. We demonstrate that these defects can alter the effective mass of charge carriers. Specifically, substitutional ${\mathrm{Se}}_{\mathrm{Bi}}$ defects, which appear under Se-rich conditions, destroy the ${\mathrm{Bi}}_2{\mathrm{O}}_2$ channel and compromise charge transport properties. These defects increase the effective mass of charge carriers transforming the original semiconductor into a semimetal and introducing holes into charge transport. Additionally, we show that single crystals are generally inhomogeneous, particularly those grown under Se-rich conditions. Unlike Se-poor conditions, Se-rich conditions induce a higher concentration of dislocations and extraneous phases. These findings suggest that the perfection of the ${\mathrm{Bi}}_2{\mathrm{O}}_2$ channel is crucial for mobility, particularly at room temperature.

We report a systematic investigation of the structural, magnetic, and magnetoelectric properties of single-crystalline ${\mathrm{MnPS}}_3$, a van der Waals honeycomb antiferromagnetic insulator. While isostructural to ${\mathrm{MnPSe}}_3, {\mathrm{MnPS}}_3$ exhibits distinct magnetic behavior characterized by a Néel temperature of $T_{\mathrm{N}}\sim 78$ K and a magnetic point group 2′/$m$ with moments oriented predominantly along the $c$ axis. Thermodynamic analysis via specific heat reveals a significant magnetic entropy release extending well above $T_{\mathrm{N}}$, indicative of robust two-dimensional short-range correlations and a two-/three-dimensional magnetic crossover. Crucially, we observe a magnetic-field-induced electric polarization $\mathrm{\Delta }{P}_z$ when a magnetic field is applied perpendicular to the $z$ direction. The $\mathrm{\Delta }{P}_z$($H$) response exhibits a pronounced and unconventional hysteretic behavior, which we attribute to the interplay between the symmetry-allowed linear ME effect and weak interlayer vdW interactions that govern magnetic domain dynamics. These findings provide fundamental insights into the symmetry-driven magnetoelectric coupling in low-dimensional systems and position ${\mathrm{MnPS}}_3$ as a versatile platform for tunable spintronic and quantum functional devices.

The cubic zincblende polymorph of InGaN is a very promising candidate for optical applications. Its absence of spontaneous polarization fields in the (001) orientation and lower fundamental band gap compared to its wurtzite counterpart makes it especially interesting for efficient light-emitting diodes (LEDs) and micro-LEDs. Therefore, understanding the optical properties and band structure of this material plays a key role in the development of possible future applications. For this, the current study presents the optical properties in the form of the dielectric function of thin film ${\mathrm{In}}_x{\mathrm{Ga}}_{1-x}\mathrm{N}$ for entire composition range $(0\le x\le 1)$. The investigated spectral regions range from the near-infrared (0.5 eV) to the vacuum ultraviolet (8.8 eV). We focus on the spectral ranges above 4 eV to study the redshift of the higher energy transition (${\mathrm{E}}_1$ at the $L$-point of the band structure and ${\mathrm{E}}_2$ at the $X$-point) as the In composition changes from GaN to InN. The characteristic energy of these transitions at critical points in the band structure are determined by a critical point model based on the third derivative of the dielectric function. Bowing fits of the ${\mathrm{E}}_1$ and ${\mathrm{E}}_2$ transitions yield bowing parameters of $b_1=1.01\mathrm{eV}$ and $b_2=0.50\mathrm{eV}$. Furthermore, we determined the dielectric limit as ${\varepsilon }_{\infty }={\varepsilon }_1(E\to 0)$, yielding a bowing parameter of $b_{\infty }=1.58$.

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.