The diffusivity of O in the melt-processed bulk-superconductors was studied. The chemical diffusion coefficients of O, as estimated from the experimental results, showed that the addition of Ag suppressed O diffusivity in melt-processed bulk-superconductors. On the other hand, the diffusion coefficients of Cu3Ba2SmO7/Ag and Cu3Ba2YO7/Ag were almost identical.

Oxygen Diffusivity in Melt-Processed SmBCO and YBCO Bulk-Superconductors. T.Yamada, H.Ikuta, M.Yoshikawa, Y.Yanagi, Y.Itoh, T.Oka, U.Mizutani: Physica C, 2002, 378-381[1], 713-7