Microwave surface resistance of YBa2Cu3O6.9 superconducting films

Abstract

The microwave surface resistance of an YBa₂Cu₃O_6.9 superconducting thick film was measured over the range 7.0–16.7 GHz at 77 K. This was done by placing a sample in a TE_01n wavemeter cavity and observing the change in selectivity of the cavity. The material’s surface resistance is of the same order of magnitude as that of silver at 77 K from 8 to 12 GHz and improves about another order at 4.2 K. The power‐law behavior of surface resistance with frequency is probably close to quadratic. This is similar to the behavior of low critical temperature superconductors.