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This work utilizes a multi-scale computational approach combining first-principles density functional theory (DFT) and Monte Carlo statistical simulations to provide fundamental insights into the impacts of vanadium (V) doping on the structural, electronic, magnetic, and thermodynamic properties of wurtzite zinc sulfide (ZnS). 2 × 2 × 2 ZnS supercells with controlled V doping concentrations from 12.5%–25% substituting zinc sites were constructed. The introduction of V dopants induces systematic expansions in lattice parameters and cell volume, attributed to the larger ionic radius of V 2 + than Zn 2 + , while the average compressibility shows minimal variation. However, V incorporation is found to soften ZnS by over 15% at higher dopant contents, increasing compliance and anisotropy. Stable ferromagnetic spin couplings emerge, mediated by host carriers without precipitating V secondary phases. The band structure develops half-metallic electronic properties with the lifting of spin degeneracy and preferential spin-up band metallicity induced by V-3d and S-3p hybridization effects. This results in 100% spin polarization at the Fermi level. Monte Carlo simulations based on a tight-binding Hamiltonian constructed from maximally localized Wannier functions to accurately calculate the exchange interactions between V spins successfully reproduce the magnetic phase transition behavior. The results confirm high Curie temperatures exceeding 300 K at 25% V, attributable to the significant strengthening of short-range ferromagnetic couplings over antiferromagnetic interactions. The integrated computational approach provides fundamental insights into the microscopic origin of carrier-mediated ferromagnetism in V-doped wurtzite ZnS dilute magnetic semiconductors. The systematic first-principles calculations and statistical mechanics modeling establish clear structure–property relationships linking V doping configurations and concentrations to tuned mechanical response, enhanced stability, electronic structure modifications, spin polarization, and magnetic ordering temperatures in ZnS. The results present design pathways and predictive capabilities to guide experimental efforts toward emerging high-performance magnetic materials for spintronic technologies. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a review and results of comparative study of the influence of Gd on some physical properties of (R 0.9 R′0.1)1−x Gd x Co2 solid solutions with R=Dy, Ho and R′=Er, Ho and x varied from 0.05 to 0.15. Powder X-ray diffraction analysis performed at room temperature revealed that all studied solid solutions solidify with the formation of a Laves-phase MgCu2-type structure (space group Fd−3m). The magnetization behavior and the magnetic transition are analyzed in terms of the Landau theory. The studies of magnetic properties and heat capacity showed that a relatively small Gd addition significantly increases T C of the compounds. The maximum percentage increase in T C, namely, ~43% was observed for (Ho0.9Er0.1)1−x Gd x Co2. However, the highest temperature was noted for the (Dy0.9Ho0.1)0.85Gd0.15Co2 solid solution; it is T C=183.4K. Below the ordering temperature, all samples are ferrimagnetically ordered; at high temperatures, they are Curie–Weiss paramagnets. Moreover, a small Gd addition eliminates the field-induced magnetic transition near T C and, as consequence, transforms the nature of magnetic transition from the first- to second-order. The magnetocaloric effect has been estimated in terms of both isothermal magnetic entropy and adiabatic temperature changes. The highest adiabatic temperature change ΔT ad=3K and highest isothermal entropy change ΔS mag=12.1J/kgK were observed for (Ho0.9Er0.1)0.95Gd0.05Co2 at ~90K in magnetic fields of 2T and 3T, respectively. A decrease in the entropy change has been observed with increasing Gd content in all studied samples. The smallest values of ΔS mag were observed for the (Dy0.9Ho0.1)1−x Gd x Co2 solid solutions. Under an external field change of from 0 to 3T, the maximum entropy change for (Dy0.9Ho0.1)1−x Gd x Co2 compounds decreases from 6.9at x=0.05–4.3J/kgK at x=0.15. The refrigerant capacity for all solid solutions (with 0.05≤x≤0.15) is reported. The effect of increasing Gd content in the solid solutions on their magnetic and magnetocaloric properties is discussed. [Copyright &y& Elsevier]

Among the double perovskite oxides, Sr 2 CrReO 6 has been attractive a lot of attention due its half-metallic ferrimagnetic nature and the highest magnetic transition temperature of 635 K. Here, we systematically investigated the influence of uniaxial strain along [100]-direction on the electronic and magnetic properties of double perovskite oxide Sr 2 CrReO 6 using first-principle calculations. Our results show that a critical tensile strain of + 2% leads the system to the ferromagnetic metallic state from half-metallic ferrimagnetic with a spin-polarization of 64%. Because, tensile strain decreases the anti-ferromagnetic coupling between Cr and Re ions, which results in ferromagnetic ordering. The admixture of Cr/Re d x 2 − y 2 , d x z , and d y z orbitals are mainly responsible for metallicity. Along with this, the total magnetic moment gets enhanced and almost close to an integral value of 5 μ B for higher tensile strains. On the other hand, compressive strains exhibit no substantial impact on the physical properties of Sr 2 CrReO 6. Moreover, it is also found that spin-polarization optimized with a further increase of tensile strains. Close to half-metallic ferromagnetic state due to tensile strain, this material shows a wide range of scientific and technological applications in spintronics. • Antiferromagnetic superexchange coupling leads the system to ferrimagnetic ground state. • A magnetic phase transition from half-metal ferrimagnetic to ferromagnetic metal occurs for +2% uniaxial strain. • Spin-polarization enhanced for tensile strains. [ABSTRACT FROM AUTHOR]

We report on the crystal structure and the magnetic properties of Mn5Sn3-xGax alloys with x = 0.1, 0.3, 0.5, 1.0, and 1.5, which were investigated by means of X-ray powder diffraction and magnetization measurements in fields up to 5 T in the temperature range 5 to 360 K. These alloys have in common that they exhibit a temperature-induced ferrimagnetic phase transition. The results indicate that all samples crystallize in the hexagonal Ni2 In-type structure with space group P63/mmc. The lattice parameters a and c of the Mn5Sn3-xGax decrease with increasing x, while the Curie temperature of these alloys increases with increasing x. All of the alloys exhibit a moderate magnetocaloric effect. Typical values are about 0.8 and 3 J/kgK at Tc = 282 K for x = 1.5 in a magnetic field change from 0 to 1 T and 0 to 5 T, respectively. [ABSTRACT FROM AUTHOR]