Vacancy-engineered half-metallicity and magnetic anisotropy in CrSI semiconductor monolayer

Abstract

By virtue of their complete spin polarization at the Fermi level, two-dimensional (2D) magnetic half-metallic materials are emerging as one of the latest wonder building blocks for spintronic applications. Using first-principles calculations, we explored how vacancy defects affect the electronic structure and magnetic properties of CrSI semiconductor monolayer. Our results indicate that the magnetic semiconductor monolayer becomes metallic with the presence of single Cr vacancies, VCr, or paired vacancies made up of Cr and nearby S atoms, VCr-S, while by introducing VS, VI, VCr-I and VS-I vacancies, the monolayer becomes a half-metallic ferromagnet with Curie temperature TC above room temperature. Compared with the pristine case that exhibits an intrinsic in-plane magnetic anisotropy with an easy axis along the [100] direction, the six types of vacancies considered in this study either enhance the in-plane anisotropy or switch it to out-of-plane. Our work implies that vacancy engineering could be a viable approach for achieving both half-metallicity and perpendicular magnetic anisotropy in structurally similar magnetic semiconductor monolayers as well as in relevant designer van der Waals heterostructures for 2D spintronic applications.