A first principles based study of the effect of uniform and tetragonal strains on half-metallicity in FeCrAs Heusler alloy

Abstract

Half-Heusler alloys are prominent material for spintronics devices as these materials usually exhibit high spin polarization. But this spin polarization is severely affected by various disorders and distortions which ultimately hinders their practical applications. This paper examines the effect of the uniaxial strain as well as the tetragonal strain on the electronic and magnetic properties of half-Heusler FeCrAs alloy. This work is carried out by using the first-principles density functional theory calculations using the Wein2k software. The results of our study show that FeCrAs alloy exhibiting AFM and FM characteristics in u- strain while showing only FM characteristics in t- strain. The Half metallicity of the FeCrAs is sensitive in negative u-strain while it is quite robust in positive u-strain and t-strain the FeCrAs. The maximum value of band gap at 0% tetragonal-strain is about 1.04 eV. The FeCrAs Heusler alloy preserve the 100% spin polarization for whole studied range of tetragonal-strain (−10% to 10%). This property may make this system a promising candidate for spin transfer torque application.