The perovskite phase SrPbO3 is important as a buffer and indicator of PbO chemical potential (at fixed pO2 ) according to the reaction: 2 SrPbO3 --> Sr2PbO4 + PbO(g) + 1/2 O2 (g), where the term PbO(g) includes several Pb-containing gaseous species. Total vapor pressures over SrPbO3 were investigated by Knudsen cell vacuum thermogravimetry in the range 650 - 950 C, using pure PbO as a calibrant. Results indicate that within this range, vapor pressures for SrPbO3 vary from ~12 % of those for pure PbO at the high temperature limit to ~21 % at the low temperature limit. Vapor pressures for SrPbO3 are higher than those reported for the perovskite phases PbTiO3 and PbZrO3 by a factors of ~ 20 to 50 and ~ 2 to 4, respectively. The slopes of the d(log p) vs. 1/T data are similar for all three perovskites, indicating similar enthalpies of vaporization . The measured SrPbO3 vapor pressures represent the maximum vapor pressures to be expected over phase assemblages with (Pb,Bi)-Sr-Ca-Cu-O (BSCCO) high Tc superconductors.
BSCCO, high Tc superconductor related perovskit, SrPbO<sub>3</sub>, vapor pressure