Characteristics of YBCO step-edge junctions fabricated by a chemical etching process

✍ Scribed by C.H. Park; J.P. Hong; I.H. Song; E.-H. Lee; C.W. Moon; S.A. Song; J.-W. Lee

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 730 KB
• Volume: 234
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90058-2

✦ Synopsis

High-T= step-edge junctions have successfully been fabricated on chemically etched MgO substrate steps. Epitaxial thin films of YBa2Cu,0,_6 have been prepared utilizing an off-axis RF magnetron sputtering method. AFM observations were made to investigate surface morphology of the etched substrate and YBCO films. The microstructures of the YBCO films were also observed by HRTEM, which clearly showed a 40" tilted grain boundary at the concave side of the step. The voltage-current characteristics, magnetic field dependence of the critical current, microwave and millimeter-wave response of the SEJs were investigated. The response of millimeter-wave cf= 94 GHz) irradiations on the SEJ clearly showed well-defined constant voltage steps of 194 pV. In addition, the characteristics of DC-SQUID made of step-edge junctions were also observed at 67 K.