Structural and magnetic properties of a new and ordered quaternary alloy MnNiCuSb (SG: F-43m)

TL;DR

This study reports the synthesis and characterization of a new ordered quaternary Heusler alloy, MnNiCuSb, with high ferromagnetic transition temperature and unique composition, expanding the family of non-Fe based Heusler alloys.

Contribution

The paper introduces a new quaternary Heusler alloy, MnNiCuSb, with detailed structural and magnetic properties, and explores related off-stoichiometric compositions.

Findings

MnNiCuSb crystallizes in F-43m space group.

It exhibits ferromagnetism with TC ~ 690K.

Off-stoichiometric variants are also ferromagnetic.

Abstract

We have synthesized a new crystallographically ordered quaternary Heusler alloy, MnNiCuSb. The crystal structure of the alloy has been determined by Rietveld refinement of the powder x-ray diffraction data. This alloy crystallizes in the LiMgPdSb type structure with F-43m space group. MnNiCuSb is a ferromagnet with a high TC ~ 690K and magnetic moment of 3.85MuB/f.u. Besides this we have also studied two other off-stoichiometric compositions; one Cu rich and the other Ni rich (MnNi0.9Cu1.1Sb and MnNi1.1Cu0.9Sb) which are also ferromagnets. It must be stressed that MnNiCuSb is one of the very few known, non-Fe containing quaternary Heusler alloys with 1: 1: 1: 1 composition.