STRUCTURAL AND ELECTRICAL-PROPERTIES OF DC BIAS SPUTTERED YBACUO FILMS

YBaCuO thin films with c-axis orientation have been deposited on (100) oriented SrTiO3 substrates by DC bias sputtering using a stoichiometr ic ceramic YBaCuO hollow cylinder. The structural and electrical prope rties of the films have been investigated as a function of the applied DC bias voltage which enabled a controlled positive-ion bombardment o f the film during growth. Up to a threshold of 35 V the films had tran sition temperatures around 90 K and bulk c-axis lattice parameters. Ab ove this threshold the c-axis lattice parameter increased and the tran sition temperature decreased. These results can be explained qualitati vely by various oxygen- and cation-disorder models.