Effect of deposition rate on properties of YBa2Cu3O7−δ superconducting thin films

Superconducting thin films of YBa2Cu3O7−δ on (100) SrTiO3 are prepared in situ by a pulsed laser deposition technique at deposition rates from 1 to 145 Å/s. Crystallinity of the films is examined by Rutherford backscattering in the channeling mode using a 2.2 MeV He+ ion beam. The backscattering minimum yield (χmin) increases with the deposition rate. A χmin of 3% is observed in the films deposited at the lowest deposition rate. Even at a deposition rate of 145 Å/s, the films show good crystallinity with χmin of 15%, indicating epitaxial growth. The x-ray diffraction measurements show that the films have strong c-axis orientation normal to the substrates. The films have metallic resistance versus temperature behavior with zero resistance temperatures of 90 K. The results indicate that the pulsed laser deposition technique could be used to deposit large-area films efficiently with adequate substrate movement.