Layer and symmetry dependent magnetism in self-intercalated ferromagnet Cr_1+xTe₂

The self-intercalated Cr_1+xTe₂ is a ferromagnetic layered material composed of alternating CrTe₂ and intercalated Cr layers. In this work, we investigate the symmetry and thickness dependent structural and magnetic properties of Cr_1+xTe₂. Exchange coupling constants, parameters required for the analysis of magnetic properties, are extracted by calculating the energies of different magnetic configurations. Investigation of different surface terminations shows that thin films terminated with CrTe₂ layers are the most stable. The direction of magnetic anisotropy depends on the thickness and termination of the thin film. When strain is applied, the exchange coupling constant between the intercalated Cr atom and its nearest neighbor Cr atoms responds in different ways with different symmetries. Our results indicate that the unique symmetry dependent magnetic properties in Cr_1+xTe₂ are mainly contributed by the intercalated Cr atoms.