Anomalous x-ray diffraction study of disorders in epitaxial films of the Heusler alloy, Co2MnGe

The authors report a study of structural and chemical disorders in a ternary combinatorial epitaxial film of Co(x)Mn(y)Gel(1-x-y) in the composition range that includes the Heusler alloy Co2MnGe, using microbeam anomalous x-ray diffraction techniques. The structural and chemical ordering of the alloy has been found to be extremely stable over a large composition range, while elemental site swapping and sublattice vacancies have been identified. A model of anomalous diffraction around the Co and Ge edges is presented and shown to make possible the identification and quantification of these disorders in an epitaxial film. (c) 2007 American Vacuum Society.