Evidence of surface barriers in single-crystalTl2Ba2CuO6superconductors
| Autor: | Fulin Zuo, Allen M. Hermann, D. Vacaru, H. M. Duan |
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| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Physical Review B. 47:5535-5538 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.47.5535 |
| Popis: | We report direct evidence of surface barriers in single crystals of Tl[sub 2]Ba[sub 2]CuO[sub 6] superconductors. Magnetization is measured as a function of temperature with magnetic field applied parallel to the [ital c] axis. For small field, a characteristic linear increase in [ital M] is observed at an onset temperature [ital T][sub 1]. For higher magnetic field, a new feature at low [ital T] is observed in the [ital M]([ital T]) data. The flux penetration temperature is retarded to a higher temperature. The penetration field [ital H][sub [ital p]] at temperature below 50 K determined by the first linear rise in [ital M]([ital T]) can be fitted with the relation [ital H][sub [ital p]]([ital T])=[ital H][sub [ital c]]exp([minus][ital T]/[ital T][sub 0]), consistent with a model where two-dimensional pancakes penetrate the Bean-Livingston barrier by thermal activation. The low critical field [ital H][sub [ital c]1][sup [perpendicular]] determined from the bulk penetration of vortices is also presented. |
| Databáze: | OpenAIRE |
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