Two-dimensional magnetic semiconductors with room Curie temperatures

Abstract

We propose two-dimensional (2D) Ising-type ferromagnetic semiconductors TcSiTe_{3}, TcGeSe_{3}, and TcGeTe_{3} with high Curie temperatures around 200–500 K. Owing to large spin-orbit couplings, the large magnetocrystalline anisotropy energy (MAE), large anomalous Hall conductivity, and large magneto-optical Kerr effect were discovered in these intriguing 2D materials. By comparing all possible 2D MGeTe_{3} materials (M=3d,4d,5d transition metals), we found a large orbital moment around 0.5μ_{B} per atom and a large MAE for TcGeTe_{3}. The large orbital moments are revealed to be from the comparable crystal fields and electron correlations in these Tc-based 2D materials. The microscopic mechanism of the high Curie temperature is also addressed. Our findings reveal the unique magnetic behaviors of 2D Tc-based materials and present a family of 2D ferromagnetic semiconductors with large MAE and Kerr rotation angles that would have wide applications in designing spintronic devices.