Surface Half-Metallicity of CrAs in the Zinc-Blende Structure

TL;DR

This study investigates the electronic and magnetic properties of bulk and surface CrAs in the zinc-blende structure, revealing its half-metallicity and surface state effects using advanced computational methods.

Contribution

It provides the first detailed analysis of CrAs in the zinc-blende phase, highlighting its half-metallic behavior and surface state impacts with ab initio calculations.

Findings

Bulk CrAs is half-ferromagnetic with 3 μB magnetic moment.

Cr-terminated surface retains half-metallicity.

As-terminated surface destroys the minority-spin gap.

Abstract

The development of new techniques such as the molecular beam epitaxy have enabled the growth of thin films of materials presenting novel properties. Recently it was made possible to grow a CrAs thin-film in the zinc-blende structure. In this contribution, the full-potential screened KKR method is used to study the electronic and magnetic properties of bulk CrAs in this novel phase as well as the Cr and As terminated (001) surfaces. Bulk CrAs is found to be half-ferromagnetic for all three GaAs, AlAs and InAs experimental lattice constants with a total spin magnetic moment of 3 $\mu_B$. The Cr-terminated surface retains the half-ferromagnetic character of the bulk, while in the case of the As-termination the surface states destroy the gap in the minority-spin band.