Fabrication and characterization of YBCO thin film on CeO2/a-plane sapphire substrate

✍ Scribed by M. Shirakawa; M. Miura; T. Ohazama; Y. Shingai; A. Saito; M. Mukaida; S. Ohshima

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 318 KB
• Volume: 412-414
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2004.02.227

✦ Synopsis

We have examined the fabrication conditions of epitaxial CeO 2 films on a-plane sapphire substrates, and also examined epitaxial growth of YBa 2 Cu 3 O 7Àd (YBCO) films on CeO 2 /a-plane sapphire substrate. The h=2h XRD analysis of these composite films revealed that grains of the CeO 2 and YBCO on CeO 2 /a-plane sapphire substrate were perpendicular to the substrate. From the /-scan XRD measurement, we found that the four 1 0 2 /-scan peaks of the YBCO film were observed and the peak positions were shifted by 45°compared with those of the CeO 2 films. From the peak shifts we could estimate that the angle between the [1 0 0] axis of the CeO 2 and the [1 0 0] axis of the YBCO was 45°. From temperature dependence of resistivity of the YBCO/CeO 2 /a-plane sapphire substrates, we obtained a zeroresistance temperature (T C ) of 88.6 K. We found that their crystallinity and critical temperature (T C ) were quite similar to those of YBCO film on CeO 2 /r-plane sapphire substrate. At the moment, YBCO thin films on a-plane sapphire are inferior to YBCO thin film on r-plane sapphire in terms of surface resistance.