First-principles investigation of half-metallic ferromagnetism of half-Heusler compounds XYZ

TL;DR

This study uses ab initio calculations to identify nine half-metallic half-Heusler compounds with potential for spintronic applications, highlighting their electronic structure, stability, and feasibility of realization in thin films.

Contribution

First-principles predictions of nine new half-metallic half-Heusler compounds with detailed analysis of their stability and half-metallicity under various conditions.

Findings

Nine half-metals with 0.07-0.67 eV gap predicted

Formation energies range from -1.32 to -0.12 eV/f.u.

Some compounds are metastable and suitable for thin film applications

Abstract

We investigate the electronic structure and magnetism of half-Heusler compounds XYZ (X, Y=V, Cr, Mn, Fe, Co and Ni; Z=Al, Ga, In, Si, Ge, Sn, P, As, and Sb) using the ab initio density functional theory calculations. Nine half-metals with half-Heusler structure have been predicted with the half-metallic gap of 0.07-0.67 eV. The calculations show that the formation energies for these nine half-Heusler compounds range from -1.32 to -0.12 eV/f.u., and for CoCrSi, CoCrGe, CoFeGe, CoMnSi, CoMnGe, FeMnGe and FeMnAs, the total energy differences between the half-Heusler structure and the corresponding ground-state structure are small (0.07-0.76 eV/f.u.), thus it is expected that they would be realized in the form of thin films under metastable conditions for spintronic applications. The stability of the half-metallicity of CoCrGe and FeMnAs to the lattice distortion is also investigated in detail.