Boosting the Curie temperature of GaN monolayer through van der Waals heterostructures

Nanotechnology. 2024 May 9;35(30). doi: 10.1088/1361-6528/ad3d64.

Abstract

The pursuit of van der Waals (vdW) heterostructures with high Curie temperature and strong perpendicular magnetic anisotropy (PMA) is vital to the advancement of next generation spintronic devices. First-principles calculations are used to study the electronic structures and magnetic characteristics of GaN/VS2vdW heterostructure under biaxial strain and electrostatic doping. Our findings show that a ferromagnetic ground state with a remarkable Curie temperature (477 K), much above room temperature, exists in GaN/VS2vdW heterostructure and 100% spin polarization efficiency. Additionally, GaN/VS2vdW heterostructure still maintains PMA under biaxial strain, which is indispensable for high-density information storage. We further explore the electron, magnetic, and transport properties of VS2/GaN/VS2vdW sandwich heterostructure, where the magnetoresistivity can reach as high as 40%. Our research indicates that the heterostructure constructed by combining the ferromagnet VS2and the non-magnetic semiconductor GaN is a promising material for vdW spin valve devices at room temperature.

Keywords: Curie temperature; magnetic anisotropy energy; spin polarisation efficiency; spin valve; van der Waals heterostructures.