Authors:A. Sebaoun, P. Satre, M. Mansori, and A. L'Honore
TG-DTA and X-ray diffraction measurements at different temperatures and under different oxygen partial pressures were carried out on the species Bi1.6Pb0.4Sr2CuO6±x, Bi1.6Pb0.4Sr2CaCu2O8±y and Bi1.6Pb0.4Sr2Ca2Cu3O10±z to analyse the influence of the oxygen chemical potential on the phase transformations. A new phase was found at isobaric invariant equilibrium for 0.5≤
/PTot≤1 at 884°C. This new phase presents a buffer effect towards oxygen exchange between superconducting oxides and the gas phase.