Determination of flux-density gradients in YBa2Cu3O7−δ superconductors using the high-resolution Faraday effect
| Autor: | Helmut Kronmüller, N. Moser, B. Gegenheimer, Michael Rudolf Koblischka |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Energy Engineering and Power Technology High resolution Yba2cu3o7 δ Condensed Matter Physics Magnetic flux Electronic Optical and Magnetic Materials law.invention symbols.namesake law Condensed Matter::Superconductivity Faraday effect symbols Electrical and Electronic Engineering Faraday cage Pinning force |
| Zdroj: | Physica C: Superconductivity. 166:36-48 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/0921-4534(90)90549-t |
| Popis: | Domain patterns of magnetic flux penetrated in YBa2Cu3O7−δ superconductors have been observed by means of a high-resolution Faraday technique. The experimental conditions for observing domain patterns with the high-resolution Faraday effect are discussed. Flux-density profiles and the related flux-density gradients were determined from an analysis of the domain patterns. An analysis of the measured flux-density gradients in single-crystals shows that twin-boundaries are not the strongest acting pinning mechanism at low temperatures. Our results support the assumption that intrinsic pinning determines the flux-density gradients and governs the critical currents. It is shown that the flux-density gradients in grains of the sintered specimens are larger than in single-crystals. The resulting thirty times greater pinning forces are measured both magneto-optically and with a SQUID-magnetometer. This behaviour may be explained by superimposed extrinsic pinning effects such as grain-boundaries. |
| Databáze: | OpenAIRE |
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