Investigation of phase stability and martensitic transformation of all-d-metal Heusler alloys Fe2CrIr and Fe2CrV

Abstract

The magnetism, elastic properties, phase stability and martensitic phase transition of the all-d-metal Heusler alloys Fe2CrIr and Fe2CrV are systematically investigated using first-principles calculations. Compound Fe2CrIr containing late transition metal atoms tends to have a Cu2MnAl (L21)-type structure and exhibits antiferromagnetism. Fe2CrV is relatively stable in the Hg2CuTi (XA)–type structure and exhibits ferromagnetism. Differences in mechanical stability under pressure arise from differences in phonon hybridisation. The response of Fe2CrIr to external pressure stems from a high pressure-induced martensitic transformation. On the contrary, the pressure inhibited the martensitic phase transition of Fe2CrV. The lower the value of C′, the more unstable the cubic phase. This work analyses in detail the different mechanical behaviours of Fe2CrIr and Fe2CrV under pressure and the mechanism of pressure-induced martensitic transformation, which may improve a new insight for pressure regulated martensitic phase transformation.