Ab initio calculations of the ferromagnetic shape memory alloy Ni–Mn–Al

Abstract

Results of the first-principles calculations of the magnetic shape-memory alloy NiMnAl are presented. The properties of a series of alloys in the composition range Ni50Mn x Al50− x with 0 ≤ x ≤ 50 were deduced from the ab initio simulations. One essential result is that the alloy is ferromagnetic in the range from 14 to 31 at.% Mn. Furthermore, the martensitic phases 2 M, 10 M, and 14 M with long-periodic structure were calculated. They are metastable in the stoichiometric Ni2MnAl alloy due to additional bonding between specific atomic sites. Their properties are discussed in terms of the density of states and their charge distribution.