Block-by-block deposition of BSCCO thin films by PLD method

It has been reported that as-deposited films of Bi cuprates fabricated by a pulsed laser deposition (PLD) method showed poor superconducting properties. We prepared Bi cuprates by block-by-block deposition using Bi-Sr-Cu-O and Ca-Cu-O targets without after-annealing. Applying this technique, we could obtain thin films of single-phase Bi-2212 and Bi-2223. But it was found that fabrication of Bi-2223 thin films was more difficult than that of Bi-2212. T-c values of 69.2 and 78.5 K were obtained for as-deposited Bi-2212 and Bi-2223, respectively at the deposition temperatures of 820 and 850 degrees C, though the crystallinity showed a maximum at lower temperatures of 750:degrees C for Bi-2212 and Bi-2223. The substrate temperature was found to influence also the surface morphology of the film.