Ab initio calculation of Co2MnSi/semiconductor (SC, = GaAs, Ge) heterostructures

Within density function theory under the generalized gradient approximation, for ideal Co2MnSi/GaAs (001) and (110) multilayer structures, the CoSi–AsGa interfaces are found to be half-metallic. While the most stable (110) CoSi–GeGe interface, for the ideal Co2MnSi/Ge multilayer systems, is near half-metallic. Given the atomic disorder in the Co2MnSi/GaAs (001) ((110)) multilayer systems with the CoSi–AsGa interface, Co anti-site defect is more readily presented at the (001) ((110)) interface. These results show that the low tunneling magnetoresistance ratio or spin injection measured in Co2MnSi/GaAs (001) (or (110)) tunnel junction in some experiments may be relevant to the interfaced Co anti-site defect as well as interfacial structure.