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

TL;DR

This study uses density functional theory to reveal that CrS2 exhibits diverse electronic and magnetic phases, which can be strain-tuned to develop energy-efficient, strain-controlled 2D spintronic devices with potential for advanced applications.

Contribution

The paper identifies CrS2 as a uniquely versatile 2D material with multiple magnetic and electronic phases, and demonstrates strain-induced control of its spintronic properties.

Findings

CrS2 has antiferromagnetic metallic, nonmagnetic semiconducting, and ferromagnetic semiconducting phases.

Strain can turn 1T' phase into spin-up or spin-down half metals.

Prototypical strain-controlled spin-valve device is proposed.

Abstract

Lateral heterostructures of two-dimensional (2D) materials, integrating different phases or materials into a single piece of nanosheet, have attracted intensive research interests in the past few years for high-performance electronic and optoelectronic devices. It also holds promises to significantly improve the performance and enable new functions of spintronic devices. It is imperative to have a 2D material possessing diverse electronic and magnetic properties that are required in spintronics. In this work, using density functional theory calculations, we surveyed all IV, V and VI group transition metal dichalcogenides (TMDs) and discovered that CrS2 has the most diverse electronic and magnetic properties: antiferromagnetic (AFM) metallic 1T phase, nonmagnetic (NM) semiconductor 2H phase, and ferromagnetic (FM) semiconductor 1T_prime phase with a Curie temperature of ~1000 K. More interestingly, we found that a tensile or compressive strain could turn 1T_prime phase into a spin-up or spin-down half metal. Such a unique feature enables designing strain-controlled spintronic devices using a single piece of CrS2 crystal with improved energy efficiency, which remains a challenge in miniaturization of spintronic devices. In-depth analysis attributed the unique strain tunability to the interplay between strain-induced lattice deformation and different spatial orientation of the spin-up/spin-down electronic orbitals. A prototypical design of a simple spin-valve logic device operated by strain is also presented.