Microwave Surface Resistance of Superconducting Yba_2Cu_3O_7-8 Thin Films

摘要

One of the serious material problems with high Tc superconductors is their granularity which greatly affects their microwave transmission (as well as absorption) properties. High quality near-epitaxial thin films of these oxide superconductors have been found to be advantageous for microwave devices due to their low conduction loss. Pulsed laser ablation deposition (PLAD) technique has been extensively used for the growth of high quality films of oxide superconductors. Work carried out at TIFR during the last several years has convincingly shown that significant improvement in microstructure, and consequently, in microwave transmission properties Of Yba_2Cu_3O_7-6- (YBCO) thin films can be realised by incorporating a small quantity (about 5/100) of Ag in the YBCO target used for PLAD.