Microwave losses and structural properties of large-area YBa/sub 2/Cu/sub 3/O/sub 7/ films on r-cut sapphire buffered with [001]/(111) oriented CeO/sub 2
| Autor: | G. Ockenfuss, R. Kutzner, Roger Wördenweber, T. Konigs, Nigel Klein, A.G. Zaitsev, C. Zuccaro |
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| Rok vydání: | 1997 |
| Předmět: |
High-temperature superconductivity
Materials science Condensed matter physics Analytical chemistry Crystal structure Condensed Matter Physics Epitaxy Electronic Optical and Magnetic Materials law.invention Surface conductivity law Sapphire Electrical and Electronic Engineering Thin film Sheet resistance Microwave |
| Zdroj: | IEEE Transactions on Appiled Superconductivity. 7:1482-1485 |
| ISSN: | 1051-8223 |
| Popis: | YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films were prepared on 2 inch in diameter (11_02) sapphire substrates buffered with CeO/sub 2/ layer of mixed [001]/(111) orientation. The thickness of the YBa/sub 2/Cu/sub 3/O/sub 7-x/ films was typically /spl sim/250 nm. The YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films exhibited smooth surfaces (peak-to-valley roughness of less than 20 nm) free of cracks and outgrowths. The critical temperatures of these films were 87-89 K, the critical current densities (2-3).10/sup 6/ A/cm/sup 2/ at 77 K and zero magnetic field. The low field microwave surface resistance (R/sub S/) of the YBa/sub 2/Cu/sub 3/O/sub 7-x/ films was measured at 18.7 GHz. Values of /spl sim/1.4 m/spl Omega/ were obtained at 77 K and |
| Databáze: | OpenAIRE |
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