Peritectic transition of a Bi-2223 superconductor was studied with TG and DTA under different heating rate (R, °C/min) 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% O2 partial pressure. Extrapolated to infinite rate, 0°C/min, Tp was 821 °C 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°C difference in Tp was found between 1 and 100% of partial oxygen pressure under 10°C/min 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.
Czechoslovak Journal of Physics 46, supp.3, pp.1499-1500