Enhancing the magnetic properties (Curie temperature and magnetic anisotropy energy) of a 2D MXene (Ca 2 C) by stacking a vdW heterostructure with silicene. †

Abstract

First-principles calculations within the spin polarized density functional theory (SP-DFT) were used to study the stability, electronic and magnetic properties of a vdW heterostructure by stacking a MXene (Ca 2 C) and silicene, forming the Ca 2 C/silicene van der Waals (vdW) heterostruture. Our results show that the Ca 2 C/silicene presents structural integrity without deformations, being a ferromagnetic metal system. The small magnetic moment (0.087µ B ) in the pristine Ca 2 C layer, which is mainly localized in the p-planar orbitals of the C atom, increases to 0.62 µ B in the Ca 2 C/silicene heterostructure due to the asymmetry in the spin of the π electrons that flow from MXene to silicene. Furthermore, the Curie temperature in the Ca 2 C/silicene heterostructure is strongly enhanced (T C = 371.34 K) and calculations of the magnetic anisotropy energy (MAE) show that it is double when the vdW heterostructure is formed. Furthermore, the easy magnetization axis changes from the planar (Ca2C monolayer) to the perpendicular direction (vdW heterostructure). The high T C and MAE opens a channel for the construction of magnetic devices using light atoms (without the presence of d and/or f electrons). In addition, the electronic and magnetic properties of the vdW heterostructure can be tailored by vertical strain.