First-principle investigations of martensitic transformation and magnetic properties in Ni24Mn17−xIn7Cux (x = 0–5) alloys

Abstract

The first-principles calculations have been used to study the effects of Cu addition on the martensitic transition and magnetic properties of Ni24Mn17−xIn7Cux (x = 0–5) alloys. The phase stability and martensitic transformation sequence were determined according to the formation energies of the austenite (A), 6-layer modulated martensite (6M) and non-modulated martensite (NM) phases with ferromagnetic (FM) or ferrimagnetic (FIM) state. The doped Cu atoms tend to occupy the excess Mn sites. When x = 1, the martensitic transformation sequence is FA → FIM 6M → FIM NM; while FA → (FM 6M) → FIM NM for 2 ≤ x ≤ 3; and FA → (FM 6M) → FM NM for x ≥ 4. The magnetostructural coupling characteristics can be found with 1 ≤ x ≤ 3. The variation of the magnetic properties for the FA, 6M and NM phases was discussed in detail from the perspective of the electronic density of states (DOS).