Magnetic Shielding Properties of Oxide Superconductors


Hiroyuki FUJIMOTO, Takumi BAN, Kaoru OHNO
Since High-Tc superconductors such as Y-sytem and Bi-system show perfect diamagnetism at above 90 K, it is expected that a magnetic field can be shielded by superconductors cooled with liquid nitrogen. Magnetic shielding effect of YBaCuO disks prepared by a sintering process and a melt process was measured at 77K. The sintered YBaCuO disk reduced a low magnetic field. On the otherhand, disk samples 16 mm in diameter and 1 mm in thickness, which were prepared by a melt process, reduced a higher magnetic field than the sintered sample, but the magnetic field came in through grain boundaries of the sample.