Restricted reversible region and strongly enhanced pinning in MPMG YBa2Cu3O7 with Y2BaCuO5 inclusions
| Autor: | S. Tanaka, T. Lægreid, Satoshi Gotoh, N. Koshizuka, Hirose Yamauchi, Hiroyuki Fujimoto, Masato Murakami, L. T. Sagdahl, Koji Yamaguchi, K. Fossheim |
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| Rok vydání: | 1991 |
| Předmět: |
Superconductivity
High-temperature superconductivity Materials science Flux pinning Condensed matter physics Energy Engineering and Power Technology Condensed Matter Physics Magnetic susceptibility Magnetic flux Electronic Optical and Magnetic Materials law.invention Magnetic field law Electrical and Electronic Engineering Electric current Order of magnitude |
| Zdroj: | Physica C: Superconductivity. 172:495-500 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/0921-4534(91)90220-s |
| Popis: | Recent work has shown that the melt-powder-melt-grown (MPMG) high temperature superconductor YBa2Cu3O7 with Y2BaCuO5 inclusions sustains unusually high critical current in the bulk. In the present paper the magnetic irreversibility line of this material is studied by AC permeability measurements. The irreversibility line is much steeper and is moved to higher temperatures compared to single crystal YBa2Cu3O7 and the reversible region between the irreversibility line and the Hc2 line is drastically shrunk. From standard flux creep analysis the pinning energy is found to be increased by one order of magnitude as compared to YBa2Cu3O7. The measurements further show that the irreversibility temperature increases in a simple logarithmic fashion with increasing frequency. The magnetic AC field response is found to be highly nonlinear even when B ac B dc ∼10 -5 . |
| Databáze: | OpenAIRE |
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