Magnetization flip in Fe-Cr-Ga system

TL;DR

This study explores how the magnetic properties and structure of Fe-Cr-Ga alloys change with composition, revealing a magnetization flip linked to atomic arrangements and magnetic transitions, supported by experimental and first-principles calculations.

Contribution

It provides new insights into the relationship between atomic configuration and magnetism in Fe-Cr-Ga alloys, including the first-principles validation of energetically favorable structures.

Findings

Abrupt change in Curie temperature and magnetization at specific composition.

Higher tolerance of Fe50Cr25Ga25 phase for Ga replacing Cr than Fe.

First-principles calculations confirm energetically favorable atomic arrangements.

Abstract

A systematic investigation about the structure and magnetism of Fe75-xCr25Gax (11<x<33) and Fe50Cr50-yGay (0<y<33) series has been carried out in this work. It shows that the parent Fe50Cr25Ga25 phase has higher tolerance for Ga replacing Cr than replacing Fe atoms. An abrupt flip of Curie temperature and magnetization in the Fe50Cr50-yGay (0<y<33) series was observed at the composition of Fe50Cr25Ga25. We proposed an explanation concerning anti-sites occupation and magnetic structure transition in this series. The induced structure is proved energetically favorable from first-principles calculations. This work can help us to understand the dependences between the crystal structure and magnetism in Fe-based Heusler compounds, and provides a method to deduce the atomic configurations based on the evolution of magnetism.