MAGNETO-STRUCTURAL TRANSITIONS: MOLECULAR DYNAMICS SIMULATIONS OF A UNITED-ATOM, MESOSCOPIC MODEL

Abstract

In this paper, we perform hybrid Langevin and molecular dynamics simulations on a two-dimensional, united-atom, mesoscopic model to obtain the phase diagram for a solid undergoing a magneto-structural transition. The interatomic exchange interactions are inspired by ab initio calculations in the Ni 2 MnGa system. The spins are updated with the help of Langevin soft spin dynamics. The nature of the phase diagram obtained from our simulations is similar to that obtained experimentally in Ni 2+x Mn 1-x Ga Heusler alloys showing magnetic and martensitic transitions with excess Ni stoichiometry viz. x.