PURPOSE: To prevent the degradation of an oxide superconductor due to moisture.
CONSTITUTION: A Pb-Si-Cd-Bi-O base glass material, which melts at 600°C or less and vitrifies, is coated on the surface of an oxide superconductive polycrystalline so as to form a vitreous protecting film. Its degradation due to the invasion of moisture can be prevented by the vitreous protecting film, so that the characteristics served by the oxide superconductive polycrystalline can be kept for a long term. And subsequently the quantity of optimum stabilizing materials can be easily selected by varying the ratio of the wire 7 to the wire 8. Whereby, the increase in the critical current density and the decrease in the AC loss can be performed while enhancing the stability and the high strength.
ISHII MAMORU
TSUKAMOTO KEIZO
YAMAGISHI SENJO
