Superconducting Bi-Sr-Ca-Cu-O Thin Films Grown by Metalorganic Chemical Vapor Deposition at Different Temperatures

Superconducting Bi-Sr-Ca-Cu-O thin films have been prepared on MgO substrates by metalorganic chemical vapor deposition using triphenylbismuth and β-diketonates of Sr, Ca and Cu as source materials. Superconducting properties, surface morphology and crystallinity of the as-deposited films are largely dependent on growth temperature. When the substrate temperature is at 800°C and over, as-deposited films show high c-axis orientation and zero resistance over 70 K. The best results to date, obtained from a film grown at 800°C show the T c onset at 110 K and zero resistance at about 80 K. On the other hand, as the substrate temperature decreases below 800°C, the temperature exhibiting zero resistance and X-ray diffraction intensity are rapidly reduced.