Tunneling, X-ray and electron diffraction studies of the structure of Nb3Ge films

In an attempt to understand the structure of high TcNb3Ge films we have utilized tunneling, x-ray diffraction and transmission electron diffraction. Tunneling experiments indicate that such films have an appreciable highly disordered component. In x-ray diffraction, only two anomalous diffraction peaks are observed which are not sufficient to identify the unknown phase. The complex electron diffraction patterns are interpreted most easily as evidence for superlattice formation. Finally we show that large lattice expansions and depressions of Tcare produced when Nb3Ge films are exposed to hydrofluoric acid, presumably due to inclusion of hydrogen.