[en] high-temperature superconductors ; magnetic measurements ; thermal measurements
[en] When YBCO single domains are subjected to a variable magnetic field, the motion of vortices may give rise to a significant temperature increase and a degradation of the superconducting properties. We have experimentally investigated such effects in bulk melt-processed YBCO single domains. Several temperature sensors, a pick-up coil and two Hall probes were placed against the surface of a monolithic bulk YBCO pellet. Data were simultaneously recorded during the application of ac magnetic fields of various amplitudes, either with or without a pre-existing dc trapped flux. The measurement results agree well with to those obtained by numerical modeling. It was also found that a superimposed dc magnetic moment reduces the temperature increase caused by the ac magnetic field. (C) 2003 IEEE.
Services Universitaires Pour la Recherche et les Applications Technologiques de Matériaux Électro-Céramiques, Composites, Supraconducteurs - SUPRATECS
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