SUPERCONDUCTIVITY AND LOCALIZATION IN THIN POLYCRYSTALLINE TUNGSTEN-GERMANIUM FILMS

We report magnetoresistance measurements on a high-resistivity (almost -equal-to 200 muOMEGA cm) crystalline material that becomes supercondu cting. Our samples are thin polycrystalline W100-xGex (x=16-18) films, measured above the superconducting transition temperature. This is an opportunity to test the predictions for electron-phonon scattering in the presence of strong elastic scattering. The films are deposited us ing a low-temperature chemical-vapor-deposition process and show the c rystalline beta-W structure (A15) with a T(c) of around 3 K and H(c2) near 8 T. Contributions from both superconducting fluctuations and wea k localization to the magnetoresistance are discussed and the inelasti c-scattering rate is found to be determined by electron-phonon scatter ing.