High temperature superconducting (HTS) Y-Ba-Cu-O (YBCO) films were prepared on MgO polycrystal substrates by the sol-gel process. The resistivity at DC and the surface resistance (Rs) at a microwave frequency of the films were measured. Rs was found to be highly dependent on the thickness of the films and the temperature, and the optimal value obtained for Rs was 4.2 mΩ at 40 K and 10 GHz. We also fabricated a YBCO coplanar waveguide (CPW) half-wavelength resonator around 2 GHz and compared its RF property with that of a normal metal. The incident power dependence of the transmission characteristics was observed to examine the power handling capability of the HTS resonator. As the temperature and the input power decreased, the quality factor (Q0) of the YBCO CPW resonator improved significantly, as opposed to hardly any change of that of a normal metal.
|ジャーナル||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|出版物ステータス||出版済み - 1 1 1997|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)