Investigations on full-Heusler alloys Mn2TaAl and Mn2WAl for spintronic and thermoelectric applications

Abstract

Half-metallic materials are widely used as spintronic devices such as electrodes, magnetic tunneling junction, and giant magnetoresistance. In this work, we have systematically investigated the structural stability, Gilbert damping, electronic structure, and magnetism together with exchange interactions and Curie temperatures for Mn₂TaAl and Mn₂WAl alloys. Initially, we estimate their structural stability and offer possible phase synthesis. Subsequently, the Gilbert damping parameters calculated by the linear response theory are used to assess their response speed as spintronic materials. Furthermore, the Mn₂TaAl and Mn₂WAl are predicted to be half-metallic and nearly half-metallic ferrimagnets and their total magnetic moments obey the Mt = Zt-18 rule. Accordingly, their Curie temperatures for Mn₂TaAl and Mn₂WAl are also evaluated by the mean-field approximation. Finally, their thermodynamic parameters within 0∼600 K and thermoelectric properties within 200∼900 K are discussed. Overall, our research for Mn₂TaAl and Mn₂WAl alloys might provide some valuable clues for their application in spintronic devices.