VClBr2: A new two-dimensional (2D) ferromagnetic semiconductor

Abstract

Magnetic van der Waals nanocrystals with intrinsic magnetic anisotropy provide an ideal platform for exploring magnetism in the low-dimensional limit. In this work, we investigated the electronic and magnetic properties of a novel 2D material VClBr2 by using spin-polarized density functional theory calculations. Various strategies were employed to tune the material properties without changing the chemical composition or introducing defects. A phase transition is observed from semiconducting → metallic → half-metallic phase with ferromagnetic and antiferromagnetic ground state(s) under the application of strain (η) and electric field (Ez). Monte-Carlo simulation based on the Heisenberg spin-chain predicted the Curie temperature (Tc) to be about 340 K under the application of an Ez=2.5 V/nm, a colossal enhancement of ∼6700% from its base value. The magnetic anisotropic energy calculation confirms the in-plane easy axis and its strain dependent modulation with a magnetization of ∼2.85 μB/V atom. The coexistence of high temperature spin-ordering along with half-metallicity, strain tunability, low formation energy, and excellent stability endow single layer VClBr2 to be of promising applications in electric field driven spin gating, room temperature spintronics, and 2D spin circuit design.