Defects in CrAs and related compounds: a route to half-metallic ferrimagnetism

TL;DR

This paper investigates how defects, specifically excess transition-metal atoms, induce half-metallic ferrimagnetism in CrAs and related compounds, which is promising for spintronic applications due to reduced stray fields.

Contribution

It reveals that excess transition-metal atoms cause half-metallic ferrimagnetism in zinc-blende structured compounds, highlighting defect control as a route to desired magnetic properties.

Findings

Excess transition-metal atoms induce ferrimagnetism.

Antiferromagnetic coupling between surplus and regular atoms.

Preventing atomic migration is crucial for maintaining half-metallicity.

Abstract

Half-metallic ferrimagnetism is crucial for spintronic applications with respect to ferromagnets due to the lower stray fields created by these materials. Studying the effect of defects in CrAs and related transition-metal chalcogenides and pnictides crystallizing in the zinc-blende structure, we reveal that the excess of the transition-metal atoms leads to half-metallic ferrimagnetism. The surplus of these atoms are antiferromagnetically coupled to the transition-metal atoms sitting at the perfect lattice sites. The needed condition to achieve half-metallic ferrimagnetism is to prevent the migration of the $sp$ atoms to other sites and the atomic swaps.