Magnetoresistance above and below Tc in c-axis-oriented YBa2Cu3O7−δ
| Autor: | Shoichi Mase, Yuuji Horie, Y.Y. Zhao, Lin Li, Yin zi Zhang, Bai ru Zhao, Lan fong Chen, Kazuyuki Shiraki, P. Xu |
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| Rok vydání: | 1990 |
| Předmět: |
Physics
Magnetoresistance Condensed matter physics Energy Engineering and Power Technology Conductivity Condensed Matter Physics Electronic Optical and Magnetic Materials Coherence length Magnetic field Electrical resistivity and conductivity Lattice (order) Empirical formula Electrical and Electronic Engineering Anisotropy |
| Zdroj: | Physica C: Superconductivity. 167:42-48 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/0921-4534(90)90482-t |
| Popis: | Electrical resistivity ϱ(T, H) of c-axis-oriented YBa2Cu3O7 − δ thin films was measured under high magnetic fields up to H = 11 T. Following a proposal about the mechanism of magnetoresistance below Tc in high-Tc oxide superconductors made in previous papers, we have shown that the peculiar anisotropic curves of magnetoresistance can be well reproduced in terms of an empirical formula. The proposal is based on an inference that the coherence length is very short, so that the flux lattice cannot be kept in a regular lattice state in higher temperature and magnetic field regions beyond the flux creep region. Some experimental evidence for this inference is stated. Based on this inference, the coherence length derived from the fluctuation conductivity above Tc is shown to be nearly equal to that from -dHc2(T)/dT at T ⩽ Tc, which was obtained from a large x% criterion in ϱ (T, H) versus T curves. |
| Databáze: | OpenAIRE |
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