Preparation of thin film YBa2Cu3O(6+x) ceramic superconductors by the sol-gel process

High-Tc superconducting powders and thin films on Si have been fabricated by the sol-gel process. Both powder and film preparation involved the synthesis of metal alkoxides, followed by the complexation of Y, Ba, and Cu alkoxides in a common solvent. Bulk gels were then vacuum dried and fired at 700 and 950 C in flowing oxygen. Thin films on (100) Si were fired at 700 C in flowing oxygen. Susceptibility vs temperature measurements showed that the thin films on Si had a Tc of 40 K, while the bulk gels fired under the same conditions had a Tc of 75 K. The sample fired at 950 C was superconducting at 90 K.