Manipulating the electronic and magnetic properties by ferroelectric polarization switching in 2D NiCl2/Ga2S3 van der Waals heterostructure

Exploring magnetoelectric coupling properties in multiferroic materials is scientifically intriguing and of great technical importance in nanoscale devices. In this work, the magnetoelectric coupling behaviors in the two-dimensional (2D) multiferroic heterostructure (HS), NiCl2/Ga2S3, are explored using density functional theory calculations. Our results show that the NiCl2/Ga2S3 HS remains in the ferromagnetic (FM) state in both ferroelectric (FE) polarization states, with the magnetic easy axis lying close to the xoz plane in the Ga2S3-P↓ state and aligning along the eclipsed z axis in the Ga2S3-P↑ state, respectively. Moreover, the HS in the Ga2S3-P↑ polarization state behaves as an FM semiconductor, while it changes to be an FM half-metal in the Ga2S3-P↓ polarization state. By applying tensile strains, the NiCl2/Ga2S3-P↓ can transit from FM quasi-half-metal to FM semiconductor with type-II band alignment. The regulation of physical properties that is induced by the FE layer in the HS originates from interfacial charge transfer due to the proximity effect. This work offers a platform to fabricate a magnetoelectric coupling interaction in 2D multiferroic devices.