high-T/sub C/ Superconducting Research Articles

Microstrip ring resonator technique for measuring microwave attenuation in high-T/sub c/ superconducting thin films

Microwave attenuation of high-T/sub c/ superconducting (HTS) films sputtered on MgO and ZrO/sub 2/ were measured using a microstrip ring resonator circuit. The results of Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O resonators were compared to those for gold-plated resonators of identical design. The losses of superconducting and gold-plated films were determined from unloaded Q-factor measurements. The attenuation of Y-Ba-Cu-O film on an MgO substrate is approximately 31% lower than that of gold films at 6.6 GHz and 33% lower at 19.2 GHz for temperatures below 50 K. The approach of using microstrips to characterize microwave losses shows the usefulness of HTS films in integrated circuit technology. >

Study and preparation of high-T/sub c/ superconducting (HTSC) thin films for electronic applications

The authors review the preparation, processing, and properties of the coevaporated Y-Ba-Cu-O thin films. In addition, they cover the fabrication of submicrometer wires and laser micromodification of these films. High-quality superconducting YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films were reproducibly prepared through thermal coevaporation of BaF/sub 2/, Y, and Cu. Uniformity in thickness and composition of the deposited films can be achieved for a 2.5-in.-diameter area. Highly c-oriented films with a total transition temperature above 90 K were reproducibly made on