RF properties of (RE)Ba2Cu3O7-δ (RE=Er, Ho, and Dy) superconducting thin films for wireless communications

We have grown and optimized several thin-film materials similar to YBCO, but with Y replaced by an alternative rare earth element. Because many of these elements sublime rather than melt readily, compositional control of these materials during deposition can be more difficult than for YBCO, which has a relatively wide process window. However, using the deposition technique of reactive coevaporation (RCE), we are able to grow high quality, epitaxial (RE)Ba₂Cu₃O_7-δ films on 2´´-diameter substrates. We will report on the growth conditions, crystal structure, and T_c values of these films. We will also discuss the Q values of lumped-element microwave resonators patterned from these films. We show that the excellent RF properties of our films make them suitable for use in wireless communications applications.