Diverse electronic and magnetic properties of CrS2 enabling strain-controlled 2D lateral heterostructure spintronic devices

Abstract

Lateral heterostructures of two-dimensional (2D) materials, integrating different phases or materials into a single piece of nanosheet, have attracted intensive research interests for electronic devices. Extending the 2D lateral heterostructures to spintronics demands more diverse electromagnetic properties of 2D materials. In this paper, using density functional theory calculations, we survey all IV, V, and VI group transition metal dichalcogenides (TMDs) and discover that CrS2 has the most diverse electronic and magnetic properties: antiferromagnetic (AFM) metallic 1T phase, non-magnetic (NM) semiconductor 2H phase, and ferromagnetic (FM) semiconductor 1T′ phase with a Curie temperature of ~1000 K. Interestingly, we find that a tensile or compressive strain can turn the 1T′ phase into a spin-up or spin-down half-metal. Such strain tunability can be attributed to the lattice deformation under tensile/compressive strain that selectively promotes the spin-up/spin-down VBM (valence band bottom) orbital interactions. The diverse electromagnetic properties and the strain tunability enable strain-controlled spintronic devices using a single piece of CrS2 nanosheet with improved energy efficiency. As a demo, a prototypical design of the spin-valve logic device is presented. It offers a promising solution to address the challenge of high energy consumption in miniaturized spintronic devices.