Tunable magnetic anisotropy, half-metallicity and tunneling magnetoresistance effect of 2D CrI3 in CrI3/MnGeX3 (X = Se, Te) heterostructures under normal compressive strain

The induction of half-metallicity and tunable magnetic anisotropy of CrI3 monolayers remains challenging and unstable. In this study, we demonstrate that half-metallic CrI3 can be induced in a CrI3/MnGeX3(X = Se, Te) heterostructure. Normal compressive (NC) strain can effectively control the half-metallic band gap and spin-polarized electronic transport of CrI3 in CrI3/MnGeSe3. At 6% strain, the half-metallic band gap and equilibrium tunneling magneto-resistance (TMR) increases by 25% and 220%. The results of band structure, force theorem, charge density and work function calculations show that CrI3 in CrI3/MnGeSe3 loses electrons to form a hole-conducting half-metal with in-plane easy magnetization axis, while CrI3 gains electrons in CrI3/MnGeTe3 to form an electron-conducting half-metal with out-of-plane easy magnetization axis. Heterointerfacial half-metallicity in CrI3 is intrinsic without any external physical modification, and the NC strain of a two-dimensional structure can easily be realized experimentally, paving the way for further research of spintronic devices.