Equiatomic quaternary Heusler alloys: a material perspective for spintronic applications

TL;DR

This paper reviews equiatomic quaternary Heusler alloys, highlighting their high spin polarization, tunable electronic structures, and potential for spintronic applications due to their unique magnetic and transport properties.

Contribution

It provides a comprehensive material perspective on EQHAs, emphasizing their structural, magnetic, and electronic features relevant for spintronic device development.

Findings

High spin polarization in EQHAs

Tunable electronic structures at room temperature

Superior magnetic and transport properties

Abstract

Half-metallic ferromagnetic (HMF) materials show high spin polarization and are therefore interesting to researchers due to their possible applications in spintronic devices. In these materials, while one spin sub band has a finite density of states at the Fermi level, the other sub band has a gap. Because of their high Curie temperature and tunable electronic structure, HMF Heusler alloys have a special importance among the HMF materials. Full Heusler alloys with the stoichiometric composition X2YZ (where X and Y are the transition metals and Z is a sp element) have the cubic structure with four interpenetrating fcc sublattices. When each of these four fcc sublattices is occupied by different atoms, a quaternary Heusler structure with different structural symmetry is obtained. Recently, these equiatomic quaternary Heusler alloys (EQHAs) with 1:1:1:1 stoichiometry have attracted a lot of attention due to their superior magnetic and transport properties.