Strain glass versus antisite disorder induced ferromagnetic state in Fe doped Ni–Mn–In Heusler martensites

Abstract

Abstract Fe doping in Ni2Mn1.5In0.5 results in suppression of the martensitic phase via two contrasting routes. In Ni2Mn1.5 − x Fe x In0.5, the martensitic phase is converted to a strain glassy phase, while in Ni2 − y Fe y Mn1.5In0.5, a cubic ferromagnetic phase results at the expense of the martensite. Careful studies of magnetic and structural properties reveal the presence of the impurity γ-(Fe,Ni) phase as the reason for the emergence of non-ergodic strain glassy phase when Fe is sought to be doped at Y/Z (Mn) sites of X2YZ Heusler alloy. Whereas attempts to dope Fe in the X (Ni) sublattice result in an A2 type antisite disorder that promotes a ferromagnetic ground state.