Strain-tunable magnetic and electronic properties of monolayer CrI3

Abstract

Two-dimensional CrI₃ has attracted much attention as it is reported to be a ferromagnetic semiconductor with a Curie temperature of around 45 K. By performing first-principles calculations, we find that the magnetic ground state of CrI₃ is variable under biaxial strain. Our theoretical investigations show that the ground state of monolayer CrI₃ is ferromagnetic under compression, but becomes antiferromagnetic under tension. Particularly, the transition occurs under a feasible in-plane strain of around 1.8%. Accompanied by the transition of the magnetic ground state, CrI₃ undergoes a transition from magnetic-metal to half-metal to half-semiconductor to spin-relevant semiconductor when the strain varies from −15% to 10%. We attribute these transitions to the variation of the d-orbitals of Cr atoms and the p-orbitals of I atoms. Generally, we report a series of magnetic and electronic phase transitions in strained CrI₃, which will help both theoretical and experimental researchers in further understanding the tunable electronic and magnetic properties of CrI₃ and its analogs.