Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub δ/ thin films on MgO annealed in a sealed capsule
| Autor: | Yorinobu Yoshisato, M. Nemoto, K. Shimaoka, Shuichi Yoshikawa, I. Yoshida, Kazuya Niki |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
High-temperature superconductivity
Materials science Scanning electron microscope Annealing (metallurgy) Analytical chemistry Dielectric Condensed Matter Physics Electronic Optical and Magnetic Materials law.invention Full width at half maximum law X-ray crystallography Dielectric loss Electrical and Electronic Engineering Thin film |
| Zdroj: | IEEE Transactions on Appiled Superconductivity. 7:1895-1898 |
| ISSN: | 1051-8223 |
| DOI: | 10.1109/77.620955 |
| Popis: | High-quality c-axis oriented Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub /spl delta// thin films have been prepared on MgO, which is more suitable for high frequency applications than LaAlO/sub 3/ because of its lower dielectric constant (/spl epsi/) and smaller dielectric loss tangent (tan /spl delta/). Annealing of the thin films was carried out in an alumina capsule sealed with a gold gasket. It was revealed that preannealing of the pellets for Tl compensation is effective in improving the structural properties of the thin films. X-ray diffraction (XRD) rocking curve scans of Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub /spl delta// (0 0 12) reflection revealed that a full width of half maximum (FWHM) of thin films annealed with an unpreannealed pellet is 0.89/spl deg/, while that of thin films annealed with a preannealed pellet is 0.22/spl deg/. The highest critical temperature (T/sub c/) is 108 K and the highest critical current density J/sub c/ is 2/spl times/10/sup 6/ A/cm/sup 2/ at 77 K. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|