Magneto-optical properties of quasi-two-dimensional MnGaGe and MnAlGe ferromagnets

Density functional theory calculations were used to investigate the magneto-optical (MO) properties of intermetallic compounds MnGaGe and MnAlGe which crystallizes in the tetragonal structure with P4/nmm space group. These compounds are formed by square-net Mn layers that exhibit an out-of-plane magnetization and are separated by two non-magnetic layers in which Ge and Ga (or Al) occupy alternating sites. They have quasi-twodimensional character like layered topological ferromagnets with Curie temperatures above room temperature and large uniaxial magnetocrystalline anisotropy, attracting attention to use in quantum spintronic devices. First principles calculations were carried out to access the electronic structure and the projected density of states for Mn 3d-orbitals. The hybridization of the Mn 3d-orbitals with host elements appears as a major factor for promoting magnetic circular dichroism, magneto-optical Kerr effect and magneto-optical Faraday effect of these Mnbased compounds. We found reasonable agreement with experimental data that confirms their potentials for applications based on spin and orbital currents.