Preparation of directly stacked YBa sub(2)Cu sub(3)O sub(7- delta )/oxide magnetic material thin films on Al sub(2)O sub(3)(0001) substrate

• Published in: Superconductor science & technology Vol. 15; no. 1; pp. 170 - 173
• Main Authors: Nishikawa, Hiroaki, Hontsu, Shigeki, Sakatani, Tomotaka, Nakamori, Masaya, Terakago, Masafumi, Mine, Shigenobu, Tabata, Hitoshi, Kawai, Tomoji
• Format: Journal Article
• Language: English
• Published: 01.01.2002
• ISSN: 0953-2048

The incorporation of magnetic material buffer layers for superconducting microwave devices is examined in order to allow Al sub(2)O sub(3) single crystal to be used as a substrate for YBa sub(2)Cu sub(3)O sub(7- delta ) (YBCO) growth and to provide functionality for microwave devices. Two magnetic materials are examined; Ni sub(0.35)Zn sub(0.65)Fe sub(2)O sub(4) (NZFO), which is a spinel-type ferrite, and Pr sub(0.8)Ca sub(0.2)MnO sub(3) (PCMO), a perovskite-type ferromagnetic material. The use of magnetic buffer layers with YBCO is applicable to magnetically controllable superconducting microwave devices. The (0001) surface of the Al sub(2)O sub(3) and [113]-oriented YBCO are used in this study due to the similarity of ion configuration at the interface. YBCO grown on Al sub(2)O sub(3)(0001) buffered with NZFO does not exhibit superconducting behaviour, whereas that grown on the PCMO buffer superconducts at a critical temperature of 87.5 K. This result indicates that PCMO is a suitable magnetic buffer layer for YBCO growth on Al sub(2)O sub(3 )(0001).