Half-metallic Antiferromagnet BaCrFeAs2

TL;DR

This paper predicts that BaCrFeAs2 is a promising half-metallic antiferromagnet with fully compensated magnetization, based on first-principles calculations and analysis of its electronic structure.

Contribution

It introduces a new candidate material, BaCrFeAs2, with unique electronic and magnetic properties due to its lattice structure and element interactions.

Findings

BaCrFeAs2 exhibits half-metallic behavior with zero net magnetization.

The material's band gap is opened in the spin channel with Fe majority carriers.

The lattice structure and hybridization are crucial for its properties.

Abstract

First-principles calculations and a tight-binding analysis predict that the iron-pnictide BaCrFeAs2 is a promising candidate for half-metallic material with fully-compensated magnetization. The transition-metal ions Cr and Fe prefer the three-dimensional intervening lattice, which yields the antiferromagnetic order of spin orientations. Due to the difference between Cr and Fe in the electronegativity, a band gap is opened at the Fermi level in the spin channel in which Fe provides the majority carriers. The selective hybridization between 3d orbitals of Cr and As:4p states due to the peculiar lattice structure of the iron-pnictide is shown to be crucial for the novel properties.