Heat Treatment of Bi(Pb)-Sr-Ca-Cu-O Thin Films Prepared by Pulsed Laser Deposition
Here, Bi(Pb)-Sr-Ca-Cu-O thin films having superconducting properties have been fabricated using Nd-YAG pulsed laser ablation onto single-crystal MgO(100) substrates. The as-deposited film was found to be in an amorphous state. The crystalline structure appeared after the film was annealed in an oxygen environment. The XRD spectrum revealed epitaxial growth of BSCCO (2212) phase at annealing temperatures of 850°C, 860°C and 870°C. In the amorphous state, the microstructure of the films exhibited spherical clusters of various sizes. Upon annealing, plate-like and needle-like structures were observed. These structures fused into grains with a plate-like shape when the annealing temperature reached 870°C. This could be due to the diffusion and arrangement of the components that make up the 2212 phase at elevated temperature in an oxygen environment. The superconducting transition temperature, Tc, is highest for samples annealed at 870°C. The post-annealing procedures were carried out in the ablation chamber in order to minimize contamination.
David J. Fisher
A.N. Jannah et al., "Heat Treatment of Bi(Pb)-Sr-Ca-Cu-O Thin Films Prepared by Pulsed Laser Deposition", Defect and Diffusion Forum, Vol. 293, pp. 47-51, 2009