Theoretical investigations on pressure-driven large-volume-change martensitic phase transition in ductile all-d-metal Heusler compound Ni2MnTa

The creation of innovative functional materials with outstanding overall performance is the main challenge encountered in practical application. This study investigated the pressure-dependent martensitic phase transition in ductile compound Ni2MnTa and also revealed its physical mechanism. Theoretically, when pressure was applied, the martensitic phase transition in Ni2MnTa was accompanied by a significant volume change of -4 %. The results indicate that the inherent volume contraction leads to enhanced interatomic d-d orbital hybridization during the tetragonal deformation, a process in which thermodynamic driving force increases significantly and deformation ability is subsequently enhanced. Their synergistic interaction induced the large-volume-change martensitic transformation in ductile all-d-metal Heusler compound Ni2MnTa. A metamagnetic martensitic phase transition could occur due to the magnetic moment difference between the austenite and marensite phases. Practically and importantly, Ni2MnTa shows better ductile properties. The combination of excellent ductility and potential large-volume-change martensitic transformation in Ni2MnTa makes it an interesting candiade material. This study can provide significant research guidance for exploring and developing novel materials for future industrial application.