Signature of half-metallicity and pressure-induced physical properties of Cubic ACr O3(A = Si,Ge,Sn) multiferroic by DFT calculation

Abstract

We report a comprehensive first-principle investigation of the structural, electronics, elastic, magnetic, and optoelectronics, and half metallicity of A=Si,Ge,SnCrO3 with space group (Pm3m) (no.221) studied for the first time based on Density Functional Theory (DFT) under pressure 0-30GPa. The tolerance factor reveals the compound cubic phase. The robust characteristics of the compound SnCrO3 found at 3.78 Å robust transition lattice constant. The optimized stable magnetic state of the compound is ferromagnetic, and by applying Born stability criteria for elastic constants, it is found that A=Si,Ge,SnCrO3 is mechanically stable in the whole pressure range. The material’s half-metallic nature is confirmed by band gaps and density of states (DOS) studies, which show that the majority spin-channel states are conducting and the minority spin-down levels are semiconducting. Moreover, bulk(B) and shear modulus(G), Poisson’s ratio(v), Cauchy pressures, Anisotropic factor(A), Plasticity measurement(B/C44) and Young's modulus(E), we found plasticity and bond distortion decreases as pressure rises and materials SnCrO3 and SiCrO3 exhibit brittleness at 0 and 10-GPa and ductile at other pressure range. On the other hand, GeCrO3 exhibits a ductile nature in the whole pressure range. The spin-polarized band structure reveals that A=Si,Ge,SnCrO3maintains a direct band (R-R) gap at the whole pressure range. Several optical properties, including dielectric function, reflectivity, refractive index, conductivity, and absorption coefficient, are also calculated. It is revealed from the real part of the dielectric function that the compound is optically metallic at low energy regions, where it exhibits a semiconducting nature at higher energy regions and plasma frequency rises with pressure. The optical properties and half-metallic response show that A=Si, Ge, SnCrO3 has intriguing properties for spintronic and optoelectronic devices.