Modulation of electronic and magnetic properties of monolayer 1T-VSe2 by ferroelectric LiNbO3 (0001) surface

Abstract

In this study, the interfacial coupling mechanism of a 1T-VSe2/LiNbO3(0001) hybrid structure and the effect of ferroelectric polarization on the electronic and magnetic properties of the 1T-VSe2 overlayer are investigated via first-principles calculations. The interfacial interaction between the 1T-VSe2 monolayer and the LiNbO3(0001) surface is found to be an ionic-vdW coupling with predominately ionic bonding. The electronic structure and magnetic properties of the 1T-VSe2 overlayer are shown to strongly depend on the ferroelectric polarization direction. The VSe2 monolayer on the thermodynamically preferred LiNbO3(0001) negative and positive surfaces exhibits the half-metallic-to-metallic electronic structure changes and the ferromagnetic-to-ferrimagnetic phase transitions, respectively, which is due to different electrostatic doping levels (−3.83 × 1013– −4.71 × 1012e/cm2). Furthermore, compared to the pristine free-standing 1T-VSe2 monolayer, a significant increase in ferromagnetic Curie temperatures is predicted for 1T-VSe2 on the LiNbO3 negative and positive surfaces and the LiNbO3 substrate after polarization reversal. These findings demonstrate that 1T-VSe2/LiNbO3 heterostructures are promising for applications in novel spintronic devices.