Interatomic orbital hybridization determined structure dependent magnetic behavior in Co-Mn-V-Ga Heusler compounds

Abstract

Structure-dependent magnetic behaviors and their controlling factor of interatomic orbital hybridization were investigated in Co2-xMnxVGa Heusler compounds. It was found that Mn atoms preferentially occupy the A Wyckoff sites in cubic L21-type structure when x < 1 due to the enhanced covalent hybridization, and then they occupy the remaining C Wyckoff sites. This atomic configuration drives relatively symmetric band filling, which suppresses the magnetic excitation and leads to weakly magnetic states in compounds near the middle composition range. In contrast, when x > 1 in Co2-xMnxVGa, the decreased covalent hybridization results in the increased slope in the composition dependent-lattice parameter curve. The theoretical results are in good agreement with current experimental observations. Interatomic orbital hybridization is also responsible for the phase stability and ductility. This study helps to deeply understand the relation between structural configurations and magnetic properties, and suggests that interatomic orbital hybridization is the key factor influencing structure-dependent magnetism in Heusler compounds.