Room temperature ferromagnetism, perpendicular magnetic anisotropy, and sizable anomalous Hall conductivity in self-intercalated bilayer 1T-CrSe2

Abstract

Two-dimensional (2D) magnetic materials exhibiting room temperature ferromagnetism have garnered significant attention due to their vast potential application and unique properties. The self-intercalated (SI) atom is a useful approach to controlling magnetic, electronic, and transport properties of 2D materials. SI Cr (CrSI) atom could effectively modulate magnetic order, Curie temperature (Tc), magnetic anisotropy properties, anomalous Hall effect (AHE), anomalous Hall conductivity (AHC), and formation energy (εf) of 1T-CrSe2, which are related to the stacking orders and concentration of CrSI atom (x). CrSI atom transforms 1T-CrSe2-BL from a spin-unpolarized metal with interlayer antiferromagnetic order to a spin-polarized metal with ferromagnetic order and presents AHE, independent of the stacking orders and x. The CrSI atom introduces local charge doping and redistribution of charge density and changes super exchange interaction between Cr and Se atoms, leading to a transfer of magnetic orders. We also find SI-1T-CrSe2 show room temperature Tc, and Cr9Se16-AA/AB have Tc of 404 and 284 K, respectively. SI-1T-CrSe2 present AHE and the corresponding sizable AHC change with the stacking orders and x. Moreover, SI-1T-CrSe2 (higher x) intends to perpendicular magnetic anisotropy, and the magnetocrystalline anisotropy (MCA) energies change with the stacking orders and x. The MCA changes as the hybridization interaction between Se-p orbitals changes. Moreover, the εf of SI-1T-CrSe2 is related to the x and chemical potential, and Cr-rich condition is beneficial to the synthesis of SI-1T-CrSe2 with CrSI atom. SI-1T-CrSe2 have good thermodynamic and kinetic stability. This work advances the research on 2D SI magnetic materials and accelerates their wide application in spintronics.