Strain Tunable Intrinsic Ferromagnetic in 2D Square CrBr$_2$

TL;DR

This study predicts that monolayer square CrBr2 is an intrinsic ferromagnetic half-metal with a high Curie temperature, tunable magnetic phases under strain, and potential for spintronic device applications.

Contribution

First-principles calculations reveal the intrinsic ferromagnetism, high Curie temperature, and strain-tunable magnetic phase transitions of monolayer square CrBr2.

Findings

CrBr2 is an intrinsic ferromagnetic half-metal with a 1.58 eV gap.

Curie temperature estimated at 212 K.

Strain induces ferromagnetic-antiferromagnetic phase transition.

Abstract

Two-dimensional (2D) intrinsic magnetic materials with high Curie temperature (Tc) coexisting with 100% spin-polarization are highly desirable for realizing promising spintronic devices. In the present work, the intrinsic magnetism of monolayer square CrBr2 is predicted by using first-principles calculations. The monolayer CrBr2 is an intrinsic ferromagnetic (FM) half-metal with the half-metallic gap of 1.58 eV. Monte Carlo simulations based on the Heisenberg model estimates Tc as 212 K. Furthermore, the large compressive strain makes CrBr2 undergo ferromagnetic-antiferromagnetic phase transition, when the biaxial tensile strain larger than 9.3% leads to the emergence of semiconducting electronic structures. Our results show that the intrinsic half-metal with a high Tc and controllable magnetic properties endow monolayer square CrBr2 a potential material for spintronic applications.