Superconducting Y-Ba-Cu-O thick films prepared by atmospheric plasma spraying technique

Superconducting Y-Ba-Cu-O thick films were successfully prepared on 304 stainless steel substrate precoated with Ni-22Cr-10A1-1Y bound coat by atmospheric plasma spraying method. Various postannealing processes were applied to restore the superconductivity of these as sprayed Y-Ba-Cu-O thick films. It was found, after the thick film was annealed at 900 degrees C in oxygen flow for 6 hours, the most optimal superconductivity exhibited onset Tc of 92 K and offset Tc of 89.5 K. In addition, feedstock powders and both the as sprayed and annealed thick films were analyzed by various characterization techniques including scanning electron microscopy, electron probe microanalyzation and x-ray fiffraction