We measured the upper critical field (B∥CuO2 plane) of optimally doped YBCO thin films (Tc~90 K) in very high magnetic fields up to 200 T generated in the single-turn coil and up to 400 T by electromagnetic flux compression. In order to overcome experimental difficulties such as high voltage induced in the measuring circuit and eddy current heating of the sample, we used a contactless radio frequency transmission technique. Clear evidence of the superconducting to normal (S-N) transition was observed for the magnetic field perpendicular to the c-axis at various temperatures. The results are consistent with our previous data obtained by means of the microwave strip-line technique. Including the data from higher fields up to 400 T, a complete magnetic phase diagram on the B-T plane has been constructed for YBCO. In addition to the S-N transition, the observed signal was found to reflect the vortex dynamics.
|ジャーナル||Physica C: Superconductivity and its applications|
|出版ステータス||Published - 2003 10|
|イベント||Proceedings of the 15th International Symposium on Superconduc - Yokohama, Japan|
継続期間: 2002 11 11 → 2002 11 13
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