关键词: self-intercalated van der Waals magnet, room-temperature ferromagnet, near half-metallicity, large anomalous Hall conductivity

Abstract: Self-intercalated van der Waals magnets, characterized by self-intercalating native atoms into van der Waals layered structures with intrinsic magnetism, exhibit a variety of novel physical properties. Here, using first-principles calculations and Monte Carlo simulations, we report a self-intercalated van der Waals ferromagnet, Cr$_{3}$Ge$_{2}$Te$_{6}$, which has a high Curie temperature of 492 K. We find that Cr$_{3}$Ge$_{2}$Te$_{6}$ is nearly half-metallic with a spin polarization reaching up to 90.9%. Due to the ferromagnetism and strong spin-orbit coupling effect in Cr$_{3}$Ge$_{2}$Te$_{6}$, a large anomalous Hall conductivity of $138 {\Omega }^{-1}\cdot {\rm cm}^{-1}$ and $305 \Omega^{-1}\cdot {\rm cm}^{-1}$ can be realized when its magnetization is along its magnetic easy axis and hard axis, respectively. By doping electrons (holes) into Cr$_{3}$Ge$_{2}$Te$_{6}$, these anomalous Hall conductivities can be increased up to $318 \Omega^{-1}\cdot {\rm cm}^{-1}$ ($648 \mathrm{\Omega }^{-1}\cdot {\rm cm}^{-1}$). Interestingly, a five-layer Cr$_{3}$Ge$_{2}$Te$_{6}$ thin film retains room-temperature ferromagnetism with a higher spin polarization and larger anomalous Hall conductivity. Our study demonstrates that Cr$_{3}$Ge$_{2}$Te$_{6}$ is a novel room-temperature self-intercalated ferromagnet with high-spin polarization and large anomalous Hall conductivity, offering great opportunities for designing nano-scale electronic devices.

Key words: self-intercalated van der Waals magnet, room-temperature ferromagnet, near half-metallicity, large anomalous Hall conductivity