Out-of-plane pressure and electron doping inducing phase and magnetic transitions in GeC/CrS2/GeC van der Waals heterostructure

Abstract

Out-of-plane pressure and electron doping can affect interlayer interactions in van der Waals materials, modifying their crystal structure and physical and chemical properties. In this study, we used magnetic monolayer 1T/1T′-CrS₂ and high symmetry 2D-honeycomb material GeC to construct a GeC/CrS₂/GeC triple layered van der Waals heterostructure (vdWH). Based on density functional theory calculations, we found that applying out-of-plane strain and doping with electrons could induce a 1T′-to-1T phase transition and consequently the ferromagnetic (FM)-to-antiferromagnetic (AFM) transition in the CrS₂ layer. Such a phase and magnetic transition arises from the pressure and electron-induced interlayer interaction enhancement. The electron doping can effectively decrease the critical compressive stress from ∼4.3 GPa (charge neutrality) to ∼664 MPa (Q = 9 × 10⁻³ e⁻ per atom) for the FM-to-AFM transition. These properties could be used to fabricate and program the 2D lateral FM/AFM heterostructures for artificial controlled spin texture and miniaturized spintronic devices.