Antisite disorder and phase segregation in Mn$_{2}$NiSn

TL;DR

This study investigates how antisite disorder and phase segregation affect the structural, magnetic, and transport properties of Mn-Ni-Sn alloys, revealing defect formation and phase separation phenomena in these materials.

Contribution

It provides a systematic analysis of defect formation and phase segregation in Mn$_{2}$NiSn alloys due to antisite disorder and annealing processes.

Findings

Antisite disorder involves Mn and Sn occupying Y and Z sublattices.

Annealing causes segregation into $L2_1$ Heusler and $D0_{19}$ Mn$_3$Sn phases.

Defects are linked to Ni substitution by Mn at X sites.

Abstract

A systematic study of crystal structure, local structure, magnetic and transport properties in quenched and temper annealed Ni$_{2-x}$Mn$_{1+x}$Sn alloys indicate the formation of Mn$_3$Sn type structural defects caused by an antisite disorder between Mn and Sn occupying the Y and Z sublattices of X$_2$YZ Heusler structure. The antisite disorder is caused by the substitution of Ni by Mn at the X sites. On temper annealing, these defects segregate and phase separate into $L2_1$ Heusler and $D0_{19}$ Mn$_3$Sn type phases.