Effect of site occupancy disorder on Martensitic properties of MnNiIn type alloys: x-ray absorption fine structure study
arXiv:1701.08561 · doi:10.1063/1.4975403
Abstract
We have carried out \textit{ab-initio} calculations of local structure of Mn and Ni in MnNiIn alloy with different site occupancies in order to understand the similarities in martensitic and magnetic properties of MnNiIn and NiMnIn alloys. Our results show that in MnNiIn alloys there is a strong possibility of Mn atoms occupying all the three, X, Y and Z sites of XYZ Heusler structure while Ni atoms preferentially occupy the X sites. Such a site occupancy disorder of Mn atoms is in addition to a local structural disorder due to size differences between Mn and In atoms which is also present in NiMnIn alloys. Further, a comparison of the calculations with experimental XAFS at the Mn and Ni K edges in MnNiIn () indicate a strong connection between martensitic transformation and occupancy of Z sites by Mn atoms.