| Autor: |
Yang Ren Sun, James R Thompson, J. G. Ossandon, J.E. Tkaczyk, David K. Christen, K. W. Lay, H. R. Kerchner, Brian C. Sales |
| Rok vydání: |
1993 |
| Předmět: |
|
| Zdroj: |
Applied Superconductivity. 1:371-380 |
| ISSN: |
0964-1807 |
| DOI: |
10.1016/0964-1807(93)90246-x |
| Popis: |
Systematic studies of flux pinning and intragrain critical current Jc were conducted in magnetically aligned, sintered Y1Ba2Cu3O7−δ material as a function of oxygen deficiency δ in the range 0 ~ 0.2. The essential findings are: 1. (1) maximum Jc occurred at full oxygenation, i.e., Jc and pinning decreased steadily as oxygen was removed; 2. (2) the irreversibility line Birr(T, δ) was degraded with the introduction of oxygen defects; 3. (3) this degradation was strongly correlated with the reduction of Jc(δ), implying that the irreversibility line is determined by the strength of the flux pinning defects; 4. (4) the condensation energy Fc decreased significantly with δ, indicating a rapid weakening in the effectiveness of pre-existing pinning centers; 5. (5) both λ and ξ increased as oxygen was removed, while 6. (6) their ratio κ and the superconductive anisotropy parameter γ = (λc/λab) ≈ 5 varied little for δ ≤ 0.2. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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