Hydrogen functionalization induced two-dimensional ferromagnetic semiconductor in Mn di-halide systems

We explored the electronic and magnetic properties of two-dimensional manganese di-halides (MnY 2 , Y = I, Br, Cl) and hydrogenated systems (MnHY 2 ). The pristine MnY 2 monolayers had a very weak magnetic exchange interaction and we found degenerated magnetic states between ferromagnetic and antiferromagnetic states although the Mn had a high magnetic moment of 5 μ B with a finite band gap. However, we found that the electronic band structure and magnetic properties could be significantly altered by functionalization with hydrogen atoms because the degeneracy in the pristine MnY 2 structure was broken and the FM ground state was obtained in all MnHY 2 systems. We obtained a negative spin polarization in the H atom and the magnetic moment of the Mn atom decreased from 5 μ B to 4 μ B . However, this negative polarization played a pivotal role in inducing a FM ground state in the MnHY 2 systems. Furthermore, the asymmetric spin dependent bang gap in MnHY 2 was also greatly enhanced due to this hydrogenation as compared with that in the pristine MnY 2 systems. This finding suggests that the hydrogenated MnHY 2 can be used as a potential ferromagnetic semiconductor for spintronics. We explored the electronic and magnetic properties of two-dimensional manganese di-halides (MnY 2 , Y = I, Br, Cl) and hydrogenated systems (MnHY 2 ).