Anomalous x-ray diffraction study of disorders in epitaxial films of the Heusler alloy Co[sub 2]MnGe

Abstract

The authors report a study of structural and chemical disorders in a ternary combinatorial epitaxial film of CoxMnyGe1−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.