Anomalous Magnetic Properties in Ni50Mn35In15

TL;DR

This study investigates the complex magnetic behavior of Ni50Mn35In15, revealing a coexistence of ferromagnetic and antiferromagnetic orders influenced by excess Mn atoms, with implications for magnetic shape memory applications.

Contribution

It provides new insights into how excess Mn atoms affect magnetic ordering and the magnetic transition behavior in Ni50Mn35In15, a Heusler alloy.

Findings

Presence of competing ferromagnetic and antiferromagnetic orders.

Excess Mn atoms influence magnetic properties and transition features.

Evidence of cluster-type magnetic inhomogeneity.

Abstract

We present here a comprehensive investigation of the magnetic ordering in Ni50Mn35In15 composition. A concomitant first order martensitic transition and the magnetic ordering occurring in this off-stoichiometric Heusler compound at room temperature signifies the multifunctional character of this magnetic shape memory alloy. Unusual features are observed in the dependence of the magnetization on temperature that can be ascribed to a frustrated magnetic order. It is compelling to ascribe these features to the cluster type description that may arise due to inhomogeneity in the distribution of magnetic atoms. However, evidences are presented from our ac susceptibility, electrical resistivity and dc magnetization studies that there exists a competing ferromagnetic and antiferromagnetic order within crystal structure of this system. We show that excess Mn atoms that substitute the In atoms have a crucial bearing on the magnetic order of this compound. These excess Mn atoms are antiferromagnetically aligned to the other Mn, which explains the peculiar dependence of magnetization on temperature.