First principles study of electronic and magnetic properties of Co ₂MnGe/GaAs interfaces

Ab initio calculations within density functional theory have been performed for the Co₂MnGe/GaAs junctions, focusing on the effect of the interface geometry on the relevant electronic and magnetic properties. Our calculations show that half-metallicity, present in bulk Co₂MnGe, is lost when the Heusler compound is deposited on the semiconducting substrate, emphasizing the importance of interface effects in the design and efficiency of spin-injection processes. Our calculated local magnetic moments on the interface atoms show that the magnetic properties are not strongly affected by the presence of the interface, except for the Co-terminated case, where the Co atoms on the bridge site show a tendency towards magnetism quenching, similar to the Fe/GaAs junction.