Studying magnetic and defect properties of two-dimensional NiI₂ layers

Magnetism is one of the most attractive properties which endows materials with not only rich physical phenomena but also potential device applications. The interplay between quantum confinement effects due to reduced dimensionality in two-dimensional (2D) materials and magnetism may further introduce interesting properties which distinguish 2D materials from their bulk counterparts. Recent years, several atomically thin magnetic materials such as CrI₃, VSe₂ and MnO₂ have been synthesized, and experimental synthetic methods advance the exploration of this field. In this work, we perform density functional theory (DFT) calculations to investigate the magnetic properties and defect effects of two-dimensional NiI₂ layers. Stacking orders and magnetic orders of NiI₂ from single-layer up to multilayers are determined, to reveal the layer-dependent effects on the magnetic properties. Also, the structures and properties of point defects and complex defects in single-layer NiI₂ are exhaustively investigated, to explore the defect effects on the magnetic properties. Furthermore, defects in multilayer NiI₂ will be examined to study the mixed effects of defects and quantum confinement.