The diffusive properties of O in systems of this form at 940C were studied by measuring the resistive response time of samples which were subjected to a step-like increase, in the O pressure, from 1 to 5 bar. The superconducting transition widths, when plotted versus the inverse diffusion constant, exhibited a linear dependence. The characteristic extended tail of the real part of the AC susceptibility, which exhibited this feature at 86K, was absent from samples with a nominal composition of Cu6Ba3Y3Ox (at resistive response times of less than 3s) due to weakly-connected grains of Cu3Ba2YO7 which nucleated from decomposed Cu6Ba3Y3Ox.

D.Djurek, V.Manojlovic, Z.Medunic, M.Prester, E.Babic, K.Zadro: Journal de Physique I, 1992, 2[1], 63-7