| タイトル | Synthesis and characterization of high-Tc superconductors in the Tl-Ca-Ba-Cu-O system |
| 著者（英） | Farrell, D. E.; Bansal, Narottam P. |
| 著者所属（英） | Case Western Reserve Univ.|NASA Lewis Research Center |
| 発行日 | 1989-05-01 |
| 言語 | eng |
| 内容記述 | Both Tl2Ca2Ba2Cu3O10 and TlCa3BaCu3O8.5 are investigated for superconductivity as a function of the sintering temperature, time, atmosphere, and quench rate in an effort to synthesize the high-Tc superconducting phase in the thallium system. The samples are characterized by electrical resistivity measurements, X-ray diffraction, and scanning electron microscopy. Samples of starting composition Tl2Ca2Ba2Cu3O10 fired in air at 860-900 C and rapidly quenched show a Tc of 96-107 K. In contrast, specimens of starting composition TlCa3BaCu3O8.5 when baked at 900 C and slowly cooled in oxygen superconduct at 116 K and above and consist of Tl2Ca2Ba2Cu3O(10+x) as the dominant phase. The results also show that, in contrast to the case of YBa2Cu3O(7-x), doping with a small concentration of fluorine sharpens the resistive transition and produces a large Tc increase in thallium-based superconductors. |
| NASA分類 | SOLID-STATE PHYSICS |
| レポートNO | 90A19300 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/359019 |
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