Title :
Deterioration mechanism of oxide superconductor
Author :
Imai, K. ; Matsuba, H.
Author_Institution :
Furukawa Electr. Co. Ltd., Yokohama, Japan
fDate :
3/1/1989 12:00:00 AM
Abstract :
Deterioration of oxide superconductors has been investigated by evaluating the critical current densities, Jc, at 77 K and the conductivity at room temperature. The oxide superconductors were exposed to both moisture and heat cycles. The authors observed slow decreases in Jc often followed by fast decreases. The experimental results indicate that an external substance penetrates into the superconductors and brings about chemical reactions to form nonsuperconducting products so that volume expansion occurs at the site causing cracks
Keywords :
barium compounds; bismuth compounds; calcium compounds; cracks; critical current density (superconductivity); electrical conductivity of crystalline semiconductors and insulators; environmental degradation; heat treatment; high-temperature superconductors; strontium compounds; yttrium compounds; 300 K; 77 K; BiSrCaCuO; YBaCuO; chemical reactions; conductivity; cracks; critical current densities; deterioration; external substance; heat cycles; high temperature superconductivity; moisture; nonsuperconducting products; oxide superconductor; room temperature; volume expansion; Atmospheric measurements; Chemicals; Conductivity; Critical current density; Electrodes; Nitrogen; Stability; Temperature; Testing; Yttrium barium copper oxide;
Journal_Title :
Magnetics, IEEE Transactions on