Dependence of microwave surface resistance on the structure of laser-deposited YBa2Cu3O7−x thin films

The effect of the structure YBa₂Cu₃O_7-x superconducting thin films on microwave surface resistance was investigated. The electon channeling patterns (ECPs) and X-ray experimental results showed that the microwave surface resistanceR_s is strongly correlated with the perfection of the thin films. The films were deposited on LaAlO₃(100) and YSZ(100) substrates. For thin film withR_s of 280µO, the crystallinity of the thin film shown byw-scanning andf-scanning was excellent and the ECPs were very sharp. For thin film with highR_s of 98 mO, only bands from the major zone were visible in the ECPs, which suggested poor crystallinity of the film. From this investigation it was shown that the more perfect the thin films, the lower theR_s.