IBAD/CVD-YBCOテープ線材のピンニング特性の超電導層厚依存性

The dependence of the transport and magnetization critical current density (Jc) characteristics on the superconducting layer thickness (d) was investigated for IBAD/CVD-processed, YBCO-coated conductors. It is believed that the decrease in Jc with increasing d in the low magnetic-field region is caused by degradation of the superconducting layer structure. The irreversibility field (Bi) increased in the low electric-field region as the thickness increased, whereas it decreased in the usual electric-field region. The apparent pinning potential (U0*) estimated using magnetic relaxation measurement also showed a complicated dependence on thickness. The results observed were approximately explained by the prediction of the flux creep-flow model.