Small interfacial distortions lead to significant changes of the half-metallic and magnetic properties in Heusler alloys: The case of the new CoFeZrSi compound

Abstract

Abstract The structural electronic and magnetic properties of CoFeZrSi material with tetragonal and triclinic distorted primitive cell were investigated within the Density Functional Theory (DFT) framework. Half-metallic soft ferromagnetism with high Curie temperature was evidenced in this quaternary compound which crystallizes optimally in the cubic LiMgPdSn type structure. The material preserves the half-metallic characteristic when the cubic primitive cell is tetragonally deformed or when the unit cell volume increases or decreases due to external applied pressure. On contrary, the energy band gap, typical for half-metals, located in the minority spin channel disappears when the unit cell is triclinic deformed, e.g. under interfacial distortions. The material exhibits metallic behavior and the total magnetic moment increases from the integral 1 μ B /f.u., calculated for cubic and tetragonal unit cells, up to 3.25 μ B /f.u. for triclinic structure with a = b = c and α = β = 90 o , γ = 89 o .