Half-metallicity in Fe2MnSi and Mn2FeSi heusler compounds: A comparative ab initio study

Abstract

First-principles calculations of the structural, electronic, and magnetic properties of full-Heusler compounds Fe2MnSi and Mn2FeSi in regular L21 and inverse XA structures have been performed using density functional theory (DFT) within generalized gradient approximation (GGA) and SCAN functionals. All compounds indicate half-metallic properties with the minority spin bandgap. The causes for the appearance of half-metallic bandgap and the difference in the electronic and magnetic properties of Heusler compounds were studied and analyzed in terms of the local environment. It is shown, that the half-metallic bandgap determines by the behavior of the t2g-electrons of A- and C-sites atoms. The behavior of the compounds under pressure was also considered. The high sensitivity of the magnetic moments on atoms A, C and the bandgap to pressure is discussed. The transition from regular to inverse structure is predicted at the negative pressure.