Thermal degradation of critical current in YBCO coated conductors

Thermal degradation of critical current in YBCO coated conductors

UGLIETTI Davide, 木吉 司 （NIMS）
uglietti.davide*nims.go.jp

Abstract:In the construction of large devices coated conductors can be exposed to high temperature， for example during soldering of current terminals. It is known that at high temperature the oxygen content in the YBCO phase decreases and the superconducting properties （among which the critical current） are degraded. The critical current of YBCO coated conductors was measured after heat treatments at various temperatures （up to 450｡・） and duration times. Copper plated tapes and silver plated tapes were studied. In copper plated tapes the degradation of the critical current is larger than in silver plated tapes. In silver plated tapes， a post-annealing in oxygen flow reintroduces oxygen in the superconducting phase， and the initial values of critical current can be recovered almost completely.

2008年秋季低温工学・超電導学会