Fe_2Ga_2S_5 as a 2D Antiferromagnetic Semiconductor

We theoretically investigate physical properties of two-dimensional (2D) Fe_2Ga_2S_5 by employing first-principles calculations. It is found that it is an antiferromagnet with zigzag magnetic configuration orienting in the in-plane direction, with Néel temperatures around 160 K. The band structure of the ground state shows that it is a semiconductor with the indirect band gap of about 0.9 eV, which could be effectively tuned by the lattice strain. We predict that the carrier transport is highly anisotropic, with the electron mobility up to the order of \sim10^3 cm^2/(V\cdots) much higher than the hole. These fantastic electronic properties make 2D Fe_2Ga_2S_5 a promising candidate for the future spintronics.