Magnetic Anisotropy of Cr2Te3: Competition between Surface and Middle Layers.

Recently, the orbital coupling in 2D materials has been demonstrated to have a significant impact on the magnetic anisotropy (MA) of CrTe2. The Te atomic layers on the surface layers determine the magnetocrystalline anisotropy (MCA) of the system due to orbital coupling. Herein, Cr2Te3$\left(\text{Cr}\right)_{2} \left(\text{Te}\right)_{3}$ is proposed to investigate the surface and middle layers of Te atoms on MA. The MCA of Cr2Te3$\left(\text{Cr}\right)_{2} \left(\text{Te}\right)_{3}$ consists of in‐plane and out‐of‐plane components, which are contributed by the surface layer and middle layer, respectively. Due to the lack of Cr–Te–Cr chemical bonds in the <italic>z</italic>‐axis, the surface layer produces px/py$p_{x} / p_{y}$ coupling and results in the in‐plane MA. In addition, a tensile strain can enhance the pz/py$p_{z} / p_{y}$ coupling on the middle layer and lead to the out‐of‐plane MCA. At the same time, the out‐of‐plane MCA breaks the vertical mirror symmetry and an anomalous Hall effect has been detected on monolayer (1L) Cr2Te3$\left(\text{Cr}\right)_{2} \left(\text{Te}\right)_{3}$. Based on this result, an anomalous Hall device is designed to record and read information. The opposing contribution of the surface and middle layers provides a completely new way to understand 2D materials. [ABSTRACT FROM AUTHOR]