The effect of wet-CO2-containing atmosphere during processing of YBCO superconductors

YBCO samples were heated to ∼ 1,000C in CO2, several mixtures of CO2 in O2, and wet CO2/O2 gas atmospheres. Thermogravimetric analysis (TGA) showed weight gains over a broad temperature range, with onset at ∼ 700C. Weight increase reached a peak value of about 4% at ∼ 900C in a 1% CO2/99% O2 atmosphere. The samples lost most of their gained weight upon heating to ∼ 1,000C. Onset of weight gain, as well as peak temperatures and amount of weight gained, depend on the heating rate. YBCO pellets were sintered in gas atmospheres similar to those used in the TGA experiments and the results will be presented