Rapid thermal processing of YBa2Cu3O7spun wires
| Autor: | J.F. Kwak, B. Morosin, Eugene L. Venturini, M. A. Mitchell, R. J. Baughman, M. J. Neal, John W. Halloran, David S. Ginley |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 67:6382-6388 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.345160 |
| Popis: | Rapid thermal processing has been utilized to sinter and anneal phase‐pure and CuO‐rich YBa2Cu3O7 fibers and woven fibers formed by melt spinning a powder/polymer composite. The optimum temperature for sintering the powders varies for the stoichiometric (1025 °C) and 5% CuO‐rich fibers (1000 °C), but in both cases the temperature window is extremely narrow (±25 °C). Typical processing consists of a rapid heating (250 °C/s) of the fibers to the sintering temperature in 1 atm of pure oxygen, holding at temperature for 1 s and cooling over a period of 2–3 min. The resulting fibers are orthorhombic YBa2Cu3O7 with large Meissner and shielding fractions, have zero resistance up to 92 K, critical‐current densities in zero applied field to 1100 A/cm2 at 76 K, and show clean grain boundaries by transmission electron microscopy. Despite the short processing times, microstructural analysis shows considerable grain growth and evidence of metastable congruent melting of oxygen‐rich YBa2Cu3O7. |
| Databáze: | OpenAIRE |
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