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Magnetic materials with non-collinear spin orderings provide an outstanding platform to probe spintronic phenomena owing to their strong spin-orbit coupling (SOC) and unique Berry phase. It is thus important to obtain a non-collinear antiferromagnetic (AFM) phase at room temperature (RT). Significantly, the discovery of novel materials with nearly zero thermal expansion (ZTE) property near RT is required and pursued for avoiding thermal stress and fracture in spintronic devices. Herein, the doping of Sn (Ge) at the Ag site in the triangular lattice Mn3Ag1−xSn(Ge)xN compounds increases effectively the Néel point and makes the interesting non-collinear Γ5g AFM phase exist above RT. The magnetic phase diagrams with Γ5g phase up to 498 K were built by the combined analysis of neutron powder diffraction (NPD), magnetic measurements, electronic transport, and differential scanning calorimetry (DSC). The thermal expansion behaviors of Mn3Ag1−xSn(Ge)xN were modulated, and the nearly ZTE above RT was achieved in Mn3Ag0.5Ge0.5N within Γ5g AFM ordering. Our findings offer an effective way to tailor the non-collinear AFM ordering and correlated thermal expansion behavior for potential use in the emerging field of thermal stress-free magnetic chip materials.

Rational design of effective, stable and low-cost oxygen evolution reaction (OER) catalysts is vital for the overall efficiency of water splitting. As a novelty branch of transition metal nitrides, antiperovskite nitrides have been considered as potential alternative OER electrocatalysts due to their high flexibility in elemental composition and excellent conductivity. Particularly, high-entropy antiperovskite nitride materials with multiple elements occupying the equivalent lattice sites are considered as potentially effective application in field of catalysis. Here, we first report the OER results about Ni-based high-entropy antiperovskite nitrides. The Cu 0.5 Fe 0.5 NNi 2 Co 0.5 Fe 0.5 as the high-entropy antiperovskite nitride is designed for an OER catalyst with promising electrocatalytical OER performance in alkaline medium (low overpotential 370 mV at 10 mA cm−2, low overpotential 627 mV at high current density of 400 mA cm−2 (almost the same overpotential with commercial RuO 2), small Tafel slope 55 mV dec−1 and long-term stability). The results provide a novel OER catalyst based on high-entropy antiperovskite metal nitrides and will push forward the strategic guidelines for design of highly efficient catalysts. Antiperovskite nitrides ANM 3 as a typical type of transition metal nitride have been considered as a potential alternative oxygen evolution reaction (OER) electrocatalyst due to their highly flexibility in elemental composition and excellent conductivity. Particularly, high-entropy antiperovskite nitride materials with multiple elements occupying the equivalent lattice sites are considered as potentially effective application in field of catalysis. Here, we first report the OER results about Ni-based high-entropy antiperovskite nitrides. The Cu 0.5 Fe 0.5 NNi 2 Co 0.5 Fe 0.5 as the high-entropy antiperovskite nitride is designed for an OER electrocatalyst with promising electrocatalytical OER performance in alkaline medium (low overpotential 370 mV at 10 mA cm−2, small Tafel slope 55 mV dec−1 and long-term stability). The results provide a novel OER electrocatalyst based on high-entropy antiperovskite metal nitrides and will push forward the strategic guidelines for design of highly efficient electrocatalysts. [Display omitted] • Antiperovskite nitrides own high flexibility in elemental composition and eminent conductivity. • High-entropy materials possess sluggish diffusion kinetics and synergistic effect of multi-component properties. • High-entropy antiperovskite Cu 0.5 Fe 0.5 NNi 2 Co 0.5 Fe 0.5 shows promising OER activities. [ABSTRACT FROM AUTHOR]

Mn-based nitrides with antiperovskite structures have several properties that can be utilized for antiferromagnetic spintronics. Their magnetic properties depend on the structural quality, composition and doping of the cubic antiperovskite structure. Such nitride thin films are usually produced by reactive physical vapor deposition, where the deposition rate of N can only be controlled by the N _2 gas flow. We show that the tuning of the N content can be optimized using low temperature resistivity measurements, which serve as an indicator of the degree of structural disorder. Several Mn _3 GaN _x films were prepared by reactive magnetron sputtering under different N _2 gas flows. Under optimized gas flow conditions, we obtain films that exhibit a metal-like temperature dependence of the resistivity, a vanishing logarithmic increase of the resistivity towards zero, the highest resistivity ratio, and a lattice contraction of 0.4% along the growth direction when heated above the Néel temperature $T_\textrm{N}$ . The retarded formation of an additional magnetic phase appearing at a temperature $T^{\ast} \ll T_\textrm{N}$ gives rise to a large thermal hysteresis of the resistivity and anomalous Hall effect.

The crystal structure of manganotychite has been refined using the holotype specimen from the Alluaiv Mountain, Lovozero massif, Kola peninsula, Russia. The mineral is cubic, Fd 3 ¯ , a = 14.0015(3) Å, V = 2744.88(18) Å3, Z = 8, R1 = 0.020 for 388 independently observed reflections. Manganotychite is isotypic to tychite and ferrotychite. Its crystal structure is based upon a three-dimensional infinite framework formed by condensation of MnO6 octahedra and CO3 groups by sharing common O atoms. The sulfate groups and Na+ cations reside in the cavities of the octahedral-triangular metal-carbonate framework. In terms of symmetry and basic construction of the octahedral-triangular framework, the crystal structure of manganotychite is identical to that of northupite, Na3Mg(CO3)2Cl. The transition northupite → tychite can be described as a result of the multiatomic 2Cl− → (SO4)2− substitution, where both chlorine and sulfate ions are the extra-framework constituents. However, the positions occupied by sulfate groups and chlorine ions correspond to different octahedral cavities within the skeletons of Na atoms. The crystal structure of northupite can be considered as an interpenetration of two frameworks: anionic [Mg(CO3)2]2− octahedral-triangular framework and cationic [ClNa3]2− framework with the antipyrochlore topology. Both manganotychite and northupite structure types can be described as a modification of the crystal structure of diamond (or the dia net) via the following steps: (i) replacement of a vertex of the dia net by an M4 tetrahedron (no symmetry reduction); (ii) attachment of (CO3) triangles to the triangular faces of the M4 tetrahedra (accompanied by the Fd 3 ¯ m → Fd 3 ¯ symmetry reduction); (iii) filling voids of the resulting framework by Na+ cations (no symmetry reduction); and (iv) filling voids of the Na skeleton by either sulfate groups (in tychite-type structures) or chlorine atoms (in northupite). As a result, the information-based structural complexity of manganotychite and northupite exceeds that of the dia net. [ABSTRACT FROM AUTHOR]

In this work, the antiperovskite semiconductor compounds Mg3XN (X = P, As, Sb, Bi) are investigated using the first-principles calculations. The structural, electronic, optical, and elastic properties of the Mg3XN compounds are studied in detail. Meanwhile, the magnetism is introduced by doping Mn element in Mg3XN compounds. Mg3XN compounds are semiconductors with direct band gap from the analysis of electronic properties. In addition, the values of band gap decrease with the increasing of atomic number of X atoms. The results of elastic parameters show that the values of bulk (91.27 GPa) and shear (76.14 GPa) modulus of Mg3PN are the largest in the Mg3XN compounds. For the velocity of sound in different directions of Mg3XN compounds, the Mg3PN has the maximum average velocity of sound, which implies that the bonding strength of Mg3PN is at maximum. Moreover, the changes of bulk modulus, shear modulus, and Young's modulus under different pressure are explored. By substituting Mg atoms with Mn atoms, the chemical formula of Mg3XN compounds is updated to Mg2.5Mn0.5XN. The conclusions of the formation enthalpy and magnetic properties of Mg2.5Mn0.5XN compounds confirm that the possibility of Mg3XN compounds becomes photovoltaic materials. We hope that the present work can provide some reference for the application of Mg3XN compounds. [ABSTRACT FROM AUTHOR]

Antiperovskites have been studied since the 1980s because of their rich physical and chemical properties, but their linear and second‐order nonlinear optical responses remain largely unknown. Here we report a new polar crystal, Cs3Cl(HC3N3S3) (I), which features a quasi‐one‐dimensional antiperovskite structure composed of ClCs6 polyhedra and A‐site [HC3N3S3]2− rings. To our best knowledge, this kind of antiperovskite structure is reported for the first time. Remarkably, I exhibits a very strong nonlinear optical response up to 11.4 times that of the benchmark KH2PO4 and exceptionally large birefringence of 0.52. The first‐principles calculations and structural analyses reveal that [HC3N3S3]2− is the "material gene" while the antiperovskite structural feature making it in a favorable arrangement. This work provides a new structural platform for the rational design of integrated optoelectronic materials with linear and second‐order nonlinear optical responses. [ABSTRACT FROM AUTHOR]

In this study, the critical behavior of the Fe-based carbide antiperovskite compound AlC1.1Fe3 has been presented. There is a second-order phase transition and the magnetic state will change from ferromagnetic state to paramagnetic state near Curie temperature. Critical exponents (β, γ, δ) representing different significance of magnetism are obtained by separate classical methods, which are exceedingly agreeable with the mean-field model theory, indicating that magnetic behavior of AlC1.1Fe3 is dominated by long-range ferromagnetic coupling. According to the scaling equation m = f ± (h), the experimental data obtained by the two experimental methods roughly overlap on the two curves, which demonstrates the reliability of these fitting parameters, and the convergence of the parameters also conforms to the mean-field model. Besides, the mutual exchange distance J(r) decreases as r−4.695 due to the competitive Fe–Fe metal bond and Fe–C covalent bond. We suggest that the competition between the localized metal bond magnetic interaction and itinerant covalent bond hybridization should be responsible for the critical behavior of AlC1.1Fe3. [ABSTRACT FROM AUTHOR]

In this study, the critical behavior of the Fe-based carbide antiperovskite compound AlC1.1Fe3 has been presented. There is a second-order phase transition and the magnetic state will change from ferromagnetic state to paramagnetic state near Curie temperature. Critical exponents (β, γ, δ) representing different significance of magnetism are obtained by separate classical methods, which are exceedingly agreeable with the mean-field model theory, indicating that magnetic behavior of AlC1.1Fe3 is dominated by long-range ferromagnetic coupling. According to the scaling equation m = f ± (h), the experimental data obtained by the two experimental methods roughly overlap on the two curves, which demonstrates the reliability of these fitting parameters, and the convergence of the parameters also conforms to the mean-field model. Besides, the mutual exchange distance J(r) decreases as r−4.695 due to the competitive Fe–Fe metal bond and Fe–C covalent bond. We suggest that the competition between the localized metal bond magnetic interaction and itinerant covalent bond hybridization should be responsible for the critical behavior of AlC1.1Fe3. [ABSTRACT FROM AUTHOR]

The crystal structure of manganotychite has been refined using the holotype specimen from the Alluaiv Mountain, Lovozero massif, Kola peninsula, Russia. The mineral is cubic, Fd3¯, a = 14.0015(3) Å, V = 2744.88(18) Å3, Z = 8, R1 = 0.020 for 388 independently observed reflections. Manganotychite is isotypic to tychite and ferrotychite. Its crystal structure is based upon a three-dimensional infinite framework formed by condensation of MnO6 octahedra and CO3 groups by sharing common O atoms. The sulfate groups and Na+ cations reside in the cavities of the octahedral-triangular metal-carbonate framework. In terms of symmetry and basic construction of the octahedral-triangular framework, the crystal structure of manganotychite is identical to that of northupite, Na3Mg(CO3)2Cl. The transition northupite → tychite can be described as a result of the multiatomic 2Cl− → (SO4)2− substitution, where both chlorine and sulfate ions are the extra-framework constituents. However, the positions occupied by sulfate groups and chlorine ions correspond to different octahedral cavities within the skeletons of Na atoms. The crystal structure of northupite can be considered as an interpenetration of two frameworks: anionic [Mg(CO3)2]2− octahedral-triangular framework and cationic [ClNa3]2− framework with the antipyrochlore topology. Both manganotychite and northupite structure types can be described as a modification of the crystal structure of diamond (or the dia net) via the following steps: (i) replacement of a vertex of the dia net by an M4 tetrahedron (no symmetry reduction); (ii) attachment of (CO3) triangles to the triangular faces of the M4 tetrahedra (accompanied by the Fd3¯m → Fd3¯ symmetry reduction); (iii) filling voids of the resulting framework by Na+ cations (no symmetry reduction); and (iv) filling voids of the Na skeleton by either sulfate groups (in tychite-type structures) or chlorine atoms (in northupite). As a result, the information-based structural complexity of manganotychite and northupite exceeds that of the dia net.

In this work, we comprehensively analyzed the structure, thermodynamics, mechanical, thermoelectric, and photoelectric properties of antiperovskite Mg 3 XN (X = As, Sb, and Bi) using first-principles calculations and semi-classical Boltzmann transport theory. Our calculations of phonon spectra and elastic constants suggest that Mg 3 XN (X = As, Sb, and Bi) exhibit excellent dynamic and mechanical stability, characterized as brittle materials with Vickers hardness (H V) values exceeding 10 GPa. Electronic structure analysis reveals that Mg 3 AsN is a direct bandgap semiconductor with a 2.25 eV gap, whereas Mg 3 SbN and Mg 3 BiN are indirect bandgap semiconductors with gaps of 1.58 eV and 1.41 eV, respectively. At room temperature, the lattice thermal conductivities (κ L) for Mg 3 AsN, Mg 3 SbN, and Mg 3 BiN are 13.63, 9.93, and 7.26 Wm−1K−1, respectively, with ZT values of 0.32, 0.08, and 0.10 at optimal doping concentrations. At 1000 K, κ L values decrease to 3.19, 2.29, and 1.65 Wm−1K−1, respectively, with ZT values reaching 2.12, 0.98, and 0.92. Our analysis of optical properties demonstrates that these materials exhibit absorbance in the visible and ultraviolet spectra, with negligible energy loss in the respective energy ranges, thereby rendering them suitable for photovoltaic applications. [ABSTRACT FROM AUTHOR]

Anti‐perovskites X3BA, as the electrically inverted derivatives of perovskites ABX3, have attracted tremendous attention for their good performances in multiple disciplines, especially in energy storage batteries. The Li/Na‐rich antiperovskite (LiRAP/NaRAP) solid‐state electrolytes (SSEs) typically show high ionic conductivities and high chemical/electrochemical stability toward the Li‐metal anode, illustrating their great potential for applications in the Li‐metal batteries (LMBs) using nonaqueous liquid electrolyte or all‐solid‐state electrolyte. The antiperovskites have been studied as artificial solid electrolyte interphase for Li‐metal anode protection, film SSEs for thin‐film batteries, and low melting temperature solid electrolyte enabling melt‐infiltration for the manufacture of all‐solid‐state lithium batteries. Transition metal‐doped LiRAPs as cathodes have demonstrated a high discharge specific capacity and good rate capability in the Li‐ion batteries (LIBs). Additionally, the underlying scientific principles in antiperovskites with flexible structural features have also been extensively studied. In this review, we comprehensively summarize the development, structural design, ionic conductivity and ion transportation mechanism, chemical/electrochemical stability, and applications of some antiperovskite materials in energy storage batteries. The perspective for enhancing the performance of the antiperovskites is also provided as a guide for future development and applications in energy storage. [ABSTRACT FROM AUTHOR]

Abstract Anti‐perovskites X3BA, as the electrically inverted derivatives of perovskites ABX3, have attracted tremendous attention for their good performances in multiple disciplines, especially in energy storage batteries. The Li/Na‐rich antiperovskite (LiRAP/NaRAP) solid‐state electrolytes (SSEs) typically show high ionic conductivities and high chemical/electrochemical stability toward the Li‐metal anode, illustrating their great potential for applications in the Li‐metal batteries (LMBs) using nonaqueous liquid electrolyte or all‐solid‐state electrolyte. The antiperovskites have been studied as artificial solid electrolyte interphase for Li‐metal anode protection, film SSEs for thin‐film batteries, and low melting temperature solid electrolyte enabling melt‐infiltration for the manufacture of all‐solid‐state lithium batteries. Transition metal‐doped LiRAPs as cathodes have demonstrated a high discharge specific capacity and good rate capability in the Li‐ion batteries (LIBs). Additionally, the underlying scientific principles in antiperovskites with flexible structural features have also been extensively studied. In this review, we comprehensively summarize the development, structural design, ionic conductivity and ion transportation mechanism, chemical/electrochemical stability, and applications of some antiperovskite materials in energy storage batteries. The perspective for enhancing the performance of the antiperovskites is also provided as a guide for future development and applications in energy storage.

The instability of the interface between solid‐state electrolytes (SSEs) and Li metal anodes is a critical factor restricting the application of NASICON‐type ionic conductors in all‐solid‐state lithium batteries (ASSLBs). Here, the lithium‐rich antiperovskite (LiRAP) Li2OHBr ionic conductor is introduced as a protective layer for the NASICON‐type solid electrolyte Li1.5Al0.5Ge1.5(PO4)3 (LAGP) by a simple way of rapid solidification of molten Li2OHBr, to prevent the adverse reaction caused by direct contact between LAGP and Li metal. The Li/Li symmetric cells with Li2OHBr protective layer exhibit long‐term cycle stability compared with the bare LAGP, and the mechanisms are analyzed by XPS measurements for the interface between SSEs and Li metal. Also, the LiFePO4/Li ASSLBs have been assembled to further demonstrate this advantage. This work shows that LiRAP Li2OHBr can improve the cycling stability of ASSLBs from the perspective of Li metal anode protection. [ABSTRACT FROM AUTHOR]

The experimental study on temperature and frequency dependent impedance spectroscopy study of an antiperovskite is being reported for the first time in this work as until now only the theoretical studies on dielectric behavior of various antiperovskites have been reported. Additionally, the effect of the presence of alkaline earth metals at A-site on the physical properties of an antiperovskite has been investigated for the first time. The structural and impedance characteristics of Mn 1.5 Y 1.5 CSr 1.5 Ba 1.5 antiperovskite, synthesized by mixed oxide method, have been reported in this work. X-Ray Diffraction (XRD) analysis of this antiperovskite indexes it in a cubic crystal system with Ia 3 ‾ space group. The impedance spectroscopy study reveals that the persistent rise in the magnitude of relative dielectric constant (ε r) and dielectric loss (tan δ), with increasing temperature, is due to thermally activated charge carriers which results in the surge in conductivity of the sample. The dielectric dispersion in this antiperovskite is ascribed to Maxwell–Wagner form of interfacial polarization that is explained on the basis of Koop's phenomenological theory. The complex impedance analysis signifies a non-Debye relaxation process for this compound. [ABSTRACT FROM AUTHOR]

In this study, we systematically investigate the electronic, magnetic, and magnetocaloric properties of Mn 3 AlN antiperovskite. This system is examined through first-principles computations using density functional theory (DFT) and Monte Carlo (MC) simulations. Based on the density of state and band structure, it is found that Mn 3 AlN behaves as a ferromagnetic metallic material. Additionally, we calculate the magnetic anisotropy and exchange interactions, which are parameters of the Hamiltonian, and incorporate them into the MC simulation. Concerning the magnetic properties, the critical temperature of the antiperovskite ( T c = 811 K) is almost similar to the experimental value ( T c = 818 K). Furthermore, we also investigate the magnetocaloric properties and find that the relative cooling power (RCP) values and maximum entropy change for a magnetic field strength of 5 T are 93.96 J/kg and 12.55 J/kg K, respectively. These results suggest that Mn 3 AlN is a promising candidate for magnetic refrigeration applications. [Display omitted] • The electronic, magnetic and magnetocaloric effect properties of Mn 3 AlN antiperovskite are studied. • The density of states and band structures were calculated using the GGA+U technique. • Mn 3 AlN can be widely used in the fields of magnetic refrigeration. [ABSTRACT FROM AUTHOR]

The development of efficient, stable and low-cost dual-function electrocatalysts and applicated it to Zn-air batteries are very important for the development of renewable energy storage and conversion technologies. Antiperovskite catalysts have attracted much attention recently due to their advantages of adjustable structure and high element selectivity. In this work, a flexible and adjustable antiperovskite catalyst ZnCCe 3−x Ni x (0 ≤ x ≤ 3) loaded on carbon fiber (ZnCCe 3−x Ni x /CNFs) was prepared by electrospinning technology and used as an air cathode catalyst for rechargeable Zn-air batteries. By doping the X-site with highly conductive transition metal Ni, the electronic structure of the catalyst ZnCCe 3−x Ni x /CNFs was optimized, and the catalytic activity of the antiperovskite bimetallic X-site was tuned to achieve an efficient and synergistic catalytic reaction. Among them, ZnCCe 2.7 Ni 0.3 /CNFs showed excellent OER/ORR bi-functional catalytic activity (Δ E = 0.82 V) and good stability. When ZnCCe 2.7 Ni 0.3 /CNFs is used as the cathode catalyst for rechargeable Zn-air batteries, it shows a power density of 117.99 mW cm−2, and the cycle stability can be maintained for up to 300 h, indicating its application potential in the field of Zn-air batteries. • Antiperovskite ZnCCe 3−x Ni x /CNFs were prepared by electrospinning method. • The OER/ORR bifunctional activity of ZnCCe 3−x Ni x /CNFs were optimized by doping Ni. • The power density of ZnCCe 2.7 Ni 0.3 /CNFs based zinc-air batteries was 117.99 mW cm−2. [ABSTRACT FROM AUTHOR]

Summary: We present a comparative study on the structural, electronic, elastic, and thermoelectric properties of the cubic inverse‐perovskites A3OX (where A = Li, Na, K and X = Cl, Br, I) by density functional theory (DFT). The cohesive, formation, and elastic properties analysis indicates that all studied materials are chemically, thermodynamically, and mechanically stable. Electronic properties reveal that all the inverse A3OX perovskite are direct bandgap semiconductors except Li3OCl and Li3OBr with ionic nature which is confirmed by electron localization function (ELF) analysis. We have also calculated Debye temperature (ΘD) and Grüneisen parameter (γ) to determine the lattice thermal conductivity for all the A3OX materials. Furthermore, thermoelectric (TE) properties are explored by calculating the Seebeck coefficient (S), electronic thermal conductivity, power factor (PF), electrical conductivity (σ/τ), lattice thermal conductivity, and ZT value. Our investigated A3OX inverse‐perovskites provide a fertile base that can improve the overall TE performance for TE applications and green energy production. [ABSTRACT FROM AUTHOR]

Ab initio computations are performed to study the structural, elastic, electronic, and vibrational characteristics of the cubic antiperovskite compound PbNCa3 under pressure up to 50 GPa. By using the generalized gradient approximation (GGA), the equilibrium structural parameters, energy band structure, density of states, elastic properties, and phonon frequencies for PbNCa3 have been examined. We have obtained some concerned feature as Young modulus and Poisson ratio for this compound using the elastic parameters. The computed elastic constant values show that PbNCa3 is stable up to 30 GPa as mechanically. To assess the stability of this compound dynamically, we have investigated the one-phonon DOS and phonon dispersion relations under pressure. Our results indicate that the calculated structural parameter values at 0 GPa are in accord with the existing data. [ABSTRACT FROM AUTHOR]

The current development of single electrocatalyst with multifunctional applications in overall water splitting (OWS) and zinc-air batteries (ZABs) is crucial for sustainable energy conversion and storage systems. However, exploring new and efficient low-cost trifunctional electrocatalysts is still a significant challenge. Herein, the antiperovskite CuNCo 3 prototype, that is proved to be highly efficient in oxygen evolution reaction but severe hydrogen evolution reaction (HER) performance, is endowed with optimum HER catalytic properties by in situ-derived interfacial engineering via incorporation of molybdenum (Mo). The as-prepared Mo-CuNCo 3 @CoN nanowires achieve a low HER overpotential of 58 mV@10 mA cm -2 , which is significantly higher than the pristine CuNCo 3 . The assembled CuNCo 3 -antiperovskite-based OWS not only entails a low overall voltage of 1.56 V@10 mA cm -2 , comparable to most recently reported metal-nitride-based OWS, but also exhibits excellent ZAB cyclic stability up to 310 h, specific capacity of 819.2 mAh g -1 , and maximum power density of 102 mW cm -2 . The as-designed antiperovskite-based ZAB could self-power the OWS system generating a high hydrogen rate, and creating opportunity for developing integrated portable multifunctional energy devices., (© 2023 Wiley-VCH GmbH.)

In this report, we have applied the muffin tin orbital method within full-potential linearized augmented plane wave approximation to investigate the intricate details of the electronic structure, elastic properties and magnetism of antiperovskite compounds Co3XN with X = Rh, Pd and Sn. The detailed analysis of the electronic structure calculations using various chemical bonding indicators suggest the covalent hybridization of the electronic states associated with Co (the high valency transition element) and the X atom (low valency transition element) as the significant interaction liable for the exhibition of the octahedral symmetry by these alloys. The large magnetic moments of Co3RhN, Co3PdN and Co3PtN are observed to be 6.20 μB, 5.20 μB and 6.21 μB, respectively; with a net magnetic moment of around 4.7 μB contributed by Co atoms in each compound. The direct exchange between Co and X atoms and indirect interaction between Co and Co via N atoms is responsible for its ferromagnetic character. The influence of the strain on the overall magnetism and relative atomic moments in the unit cell is also investigated. The anisotropic nature of these alloys and the mechanical properties like ductility increases from Rh > Pd > Pt. Also, the Debye temperatures of Co3RhN, Co3PdN and Co3PtN are calculated to be 702 K, 689 K and 606 K, respectively.

In this paper, the structure and magnetic behaviour of antiperovskite In x Fe 4- x N have been investigated systematically. The crystal lattice becomes larger and the Curie temperature decreases with increasing x. The magnetic state changes from a ferromagnetic to a glassy state. In addition, an obvious spin glass (SG) behaviour has been revealed in In 0.6 Fe 3.4 N (x = 0.6) with a freezing temperature of T 0 = 73 K, dynamical exponent of zν = 5.51, and flipping time of τ 0 = 4.26 × 10−11 s. The origin of the SG behaviour in In 0.6 Fe 3.4 N may be attributed to atomic disorders at Wyckoff position 1 a or ferromagnetic frustrations, or the both. [ABSTRACT FROM AUTHOR]

Negative thermal expansion (NTE) materials can compensate for the coefficient of thermal expansion (CTE) of normal metals. Currently, it is challenging to prepare NTE/metal composites facing the practical demands. We report the tunable CTEs between –0.39 and 6.19 ppm/K around room temperature in Zn/Si/Zn 0.75 Sn 0.2 Mn 0.05 NMn 3 composites. The low-melting Zn acts as the adhesive, while Zn 0.75 Sn 0.2 Mn 0.05 NMn 3 is the CTE compensator. Moreover, the composites have high compression strength (225 MPa) and thermal conductivity (52 W/K m), showing great potentials as electronic thermal management materials. Our results suggest an effective way to realize low-CTE composites with excellent performance based on NTE compounds. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Antiperovskite materials based on M n 3 C u N with Cu partially replaced by Ag or Ni and simultaneous substitution of N by C were synthesized and their magneto-structural transition was studied. By replacing Cu partially with Ag or Ni, Curie temperatures increase, the magnetostructural transition becomes isosymmetric and presents a more second order character. Simultaneous replacement of N by C reverses this trend as the Curie temperature decreases with increasing Ag/Ni content while the structural transition remains non-isosymmetric. Additionally, moderate magnetocaloric effects with magnetic entropy changes around 6 J/Kkg in the range of 130–150 K at a 2 T field change are observed. Finally, the influence of the change in number of valence electrons and cell size by substitution on the transition is discussed. • 8 previously unknown antiperovskite materials based on M n 3 C u N have been studied. • Low T XRD reveals that symmetry below T T depends on degree of N substitution by C. • Also, C content reverses trends seen in T C when Cu is substituted by Ag/Ni. • A Δ S M around 6 J/Kkg in the range of 130–150 K at a 2 T field changes is observed. • The influence of N(VE) and cell size on the FOMST is comprehensively discussed. [ABSTRACT FROM AUTHOR]

The present study is focused on a relatively new class of solid-state lithium halide electrolytes with antiperovskite crystal structure that are designed to alleviate safety concerns related to conventional lithium-ion batteries. The solid-state Li 3 ClO electrolyte membranes were produced by a casting/delamination method and deposited on a graphite-based working electrode. The electrolyte charge transfer resistances, electrochemical performance, and chemical stability in a half-cell configuration were evaluated over a broad temperature range from room temperature up to 100 °C. The electrochemical cells with lithium metal as a reference electrode demonstrated linear Arrhenius behavior in the temperature range of 25–100 °C confirming the absence of phase transformations. Cyclic voltammetry at 50 °C and 100 °C confirms that the electrochemical cell performance during lithiation/delithiation from 0.05 to 1.00 V is reproducible within at least 100 cycles. The solid-state electrolyte electrochemical stability in contact with lithium metal is confirmed for the first time by demonstrating the constant values of charge transfer resistances during charge/discharge operations in 575 cycles at 50 °C and 1/5 C -rate. Transport of lithium ions between the lithium metal and Li 3 ClO electrolyte in contact with a graphite working electrode provides evidence that lithium halide antiperovskites can serve as effective and electrochemically stable electrolytes for a new generation of all-solid-state lithium-ion or lithium metal batteries. Image 1031 • A solid-state electrolyte with antiperovskite structure was tested in a half-cell vs. lithium anode. • Electrolyte chemical stability in presence of Li-metal at 50 °C is confirmed by AC impedance. • Continuous cycling within 6 months at 50 and 100 °C demonstrate >80% specific capacity retention. [ABSTRACT FROM AUTHOR]

Using first-principles calculations, in this work we report the structural, electronic and, for the first time, thermoelectric properties of CuNMn3 cubic antiperovskite. The structural properties are explored using GGA and GGA+U approximations. Structural optimization shows that the compound is stable in the ferrimagnetic phase, and the electronic properties confirm the metallicity of this compound. At room temperature, high values of the Seebeck coefficient are obtained between - 0.8 and 0.5 μ(eV) chemical potential, whereas outside this region the Seebeck coefficient diminishes. Also, thermal conductivities are minimal in this region of chemical potential; therefore, the material can be used to achieve thermocouples. Thermal conductivity is high for 900 K. The maximum electrical conductivity is obtained at 0.38 μ(eV) chemical potential, with a value of 4.15×1020(Ωms)-1. The figure of merit ZT values obtained are still low, so for thermoelectric applications of the material, it is necessary to improve the figure of merit coefficient by doping the material with a suitable element. [ABSTRACT FROM AUTHOR]

Abstract: Electroresistance has become a stimulating research topic because of its potential applications in next‐generation nonvolatile memory technology. Here, an electroresistance‐like behavior of the antiperovskite Mn3GaC compound around the antiferromagnetic–intermediate phase transition is reported. A high sensing current significantly decreases the fraction of the antiferromagnetic phase of higher resistivity relative to the intermediate phase of lower resistivity upon warming, showing a resistivity change up to 50%. Through extensive studies of the resistivity at different sample locations and of the magnetization under applied current, it is unambiguously shown that this electroresistance‐like behavior originates from the local Joule heating of the sample due to high‐resistive lead contacts and not from an intrinsic effect. These findings open an available avenue to explore electroresistance‐like behavior by achieving phase coexistence of a high‐ and low‐resistivity phase under the driving force of local Joule heating. [ABSTRACT FROM AUTHOR]

The substitution of Mn for Zn was found to broaden the abnormal lattice shrinkage in Zn 1− x Mn x NMn 3 . When x = 0.3, a large constant coefficient of negative thermal expansion (NTE) α L is found between 74 K and 150 K, which, though rare, is beneficial to practical applications of NTE materials. The magnetism studies indicate that the ferromagnetic clusters appear in the paramagnetic (PM) region and restrain the transformation from PM to antiferromagnetic (AFM), leading to the broadened NTE window. Moreover, the sample x = 0.3 shows a linear PM-AFM transformation in the whole NTE window, resulting in the constant α L . [ABSTRACT FROM AUTHOR]

Materials in the Na-rich antiperovskite family are promising candidates as solid electrolytes (SEs) for all-solid-state Na-ion batteries (NIBs). In this work, we carry out ab-initio calculations to study various properties of Na 3 OCl , namely the formation energies of various neutral defect pairs, the defect hopping barriers, the solution energies of high valence alkali earth metal substitutes to the Na atoms, and the effect of such substitution to the Na migration. While the introduction of alkali earth metal ions increases the Na vacancy concentration, the activation energy of Na transport also increases. Furthermore, we identify Ca as the most promising alkali earth metal to be doped into Na 3 OCl due to its low binding energy and relatively small impact on the migration barrier. Our work provides a theoretical framework for further improving the Na conductivity of materials in the antiperovskite family for all-solid-state NIBs. [ABSTRACT FROM AUTHOR]

The structural, magnetic and magnetocaloric properties of the antiperovskite materials M n 3 C u N 1 − x C x have been studied. Substituting N with C increases the temperature of the magnetostructural transition between a paramagnetic cubic high temperature phase and a ferrimagnetic tetragonal low temperature phase. Furthermore, the first order character of the phase transition is retained upon substitution with a hysteresis below 2 K for all compositions. The magnetostructural transition gives rise to giant magnetocaloric effects in a tunable 30 K temperature range with a maximum entropy change of 11.8 J/Kkg at a 2 T field change, making these compounds promising for low temperature magnetic refrigeration applications. [ABSTRACT FROM AUTHOR]

The structure, magnetic and electronic transport properties of the compounds Mn 3 Sn 1- x Zn x C (0 ≤ x ≤ 0.5) are investigated. The studies have shown that Zn-doping in the anti-perovskite structure Mn 3 SnC reduces the cell parameter, but the compounds Mn 3 Sn 1- x Zn x C remain cubic anti-perovskite structure. When the temperature is reduced, the magnetization curve changes from PM-FM for Mn 3 SnC and Mn 3 Sn 0.9 Zn 0.1 C into PM-FM-AFM for Mn 3 Sn 1- x Zn x C(x ≥ 0.2). With the increase of doping amount x, both the Tc and the T T reduce, but when x = 0.5, they are raised. In addition, the magnetization of Mn 3 Sn 1- x Zn x C is reduced as the doping amount increases. For Mn 3 Sn 1- x Zn x C(x = 0, 0.1, 0.2,0.3, 0.4, 0.5) compounds, there exists an anomalous increase in resistivity at a certain temperature that is in agreement with their magnetic transition temperature, and doping Zn in Mn 3 SnC reduces the resistivity of Mn 3 SnC. [ABSTRACT FROM AUTHOR]

The magnetic, electrical transport and thermal expansion properties of Mn3Zn1−xCoxN (x = 0.2, 0.4, 0.5, 0.7, 0.9) have been systematically investigated. Co-doping in Mn3ZnN complicates the magnetic interactions, leading to a competition between antiferromagnetism and ferromagnetism. Abrupt resistivity jump phenomenon and negative thermal expansion behavior, both associated with the complex magnetic transition, are revealed in all studied cases. Furthermore, semiconductor-like transport behavior is found in sample x = 0.7, distinct from the metallic behavior in other samples. Below 50 K, resistivity minimum is observed in samples x = 0.4, 0.7, and 0.9, mainly caused by e-e scattering mechanism. We finally discussed the strong correlation among unusual electrical transport, negative thermal expansion and magnetic transition in Mn3Zn1−xCoxN, which allows us to conclude that the observed unusual electrical transport properties are attributed to the shift of the Fermi energy surface entailed by the abrupt lattice contraction. [ABSTRACT FROM AUTHOR]