Two-dimensional ferromagnetic semiconductor Cr2XP: First-principles calculations and Monte Carlo simulations

TL;DR

This paper designs and analyzes a new 2D ferromagnetic semiconductor Cr2XP with high Curie temperatures, large magnetization, and stability, using first-principles calculations and Monte Carlo simulations to explore its properties for spintronic applications.

Contribution

It introduces a novel 2D ferromagnetic semiconductor Cr2XP with high Curie temperatures and detailed theoretical analysis of its electronic and magnetic properties.

Findings

Curie temperatures up to 400 K estimated for Cr2SbP

Large magnetic moments (~6.16-6.37 μB) from Cr-d electrons

Cr2XP exhibits excellent stability and potential for spintronics

Abstract

According to the Mermin Wagner theorem, two-dimensional material is difficult to have the Curie temperature above room temperature. By using the method of band engineering, we design a promising two-dimensional ferromagnetic semiconductor Cr2XP (X=P, As, Sb) with large magnetization, high Curie temperature and sizable band gap. The formation of gap is discussed in terms of the hybridizations, occupation and distribution of electronic states and charge transfer. Large magnetic moments about 6.16~6.37uB origin from the occupation of Cr-d electrons in crystal field.Competition and cooperation between d-d (Cr-d~Cr-d) and d-p-d (Cr-d~X-p~Cr-d) exchange interactions lead to the emergence of ferromagnetic ordering phase. Furthermore, Curie temperatures, approaching to 269 K, 332 K and 400 K for Cr2P2, Cr2AsP and Cr2SbP, are estimated by employing Monte Carlo simulation based on the Heisenberg model. Magnetic anisotropy energy of Cr2XP is determined by calculating the total energy dependence on the angle along different directions, and the origin is also discussed by the second-order perturbation theory. In addition, the Cr2XP possesses excellent thermodynamical, dynamical and mechanical stabilities, and can overcome their own gravity to keep their planar structure without the support of substrate. These above-mentioned advantages will offer some valuable hints for two-dimensional ferromagnetic semiconductor Cr2XP in spintronic devices.