No abstract

Peritectic transition of a Bi-2223 superconductor was studied with TG and DTA under different heating rate (R, ~ and oxygen partial pressures. Linear relationships were observed between Tp (peritectic transition temperature) vs. R, and weight loss (equivalent to the O-atom loss per mole) vs. R under 25 mL/min in flowing 1% 02 partial pressure. Extrapolated to infinite rate, 0 ~ Tp was 821 ~ found from the peak temperature of the DTA curves, and 1.49 O-atom loss. Increasing oxygen partial pressure, Tp was increased but the weight loss was decreased. About 60 ~ difference in Tp was found between 1 and 100 % of partial oxygen pressure under 10~ heating rate. Only 0.26 O-atom loss was observed under 100 % oxygen partial pressure. Stability of Bi-2223 superconductor around its peritectic point was greatly enhanced by increasing the oxygen partial pressure.