Structure and magnetic properties of Heusler alloy Fe2NiZ (Z=Al, Ga, Si and Ge)

TL;DR

This study synthesizes and analyzes Fe2NiZ Heusler alloys (Z=Al, Ga, Si, Ge), revealing how covalent bonding influences their stability and magnetic properties through experimental and theoretical approaches.

Contribution

It provides new insights into how covalent p-d hybridization affects phase stability and magnetic behavior in Fe2NiZ alloys.

Findings

Covalent p-d hybridization is crucial for structural stability.

Main group elements Si and Ge induce stronger covalent effects.

Physical properties correlate with covalent character.

Abstract

The Heusler alloys Fe2NiZ (Z=Al, Ga, Si and Ge) have been synthesized and investigated focusing on the phase stability and the magnetic properties. The experimental and theoretical results reveal the covalent bonding originated from p-d hybridization takes an important role in these alloys, which dominates the stability of ordered structure but leads to the decline of the band splitting. The electronic structure shows the IV group main group element (Si and Ge) provides stronger covalent effect than that of the III group element (Al and Ga). It has been found that the variations of the physical parameters, lattice constants, critical ordering temperature, magnetic moments and Curie temperature, precisely follow these covalent characters.