First-principles electronic structure and magnetic properties of M/GaAs/M (001) heterostructures with M = Fe or Co

The electronic structure and magnetic properties of M/GaAs/M/ multilayer systems with M = Fe or Co have been studied by means of a first-principles Green's function technique. The results show that the magnetic behaviour of interface Fe atoms is sensitive to the terminations of the GaAs semiconducting spacer. Thus, in case of Ga terminations the iron magnetic moment increases over its bulk value while for As terminations it remains almost unchanged. At the Co/GaAs interfaces the cobalt magnetic moment is reduced compared with corresponding bulk value and it seems to be less sensitive to the terminations. The exchange coupling between M magnetic slabs is also influenced by terminations.