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Phase Equilibria near (Bi,Pb)‐2223, As a Function of Oxygen Partial Pressure
Author(s) -
MacManusDriscoll Judith L.,
Yi Zhuan
Publication year - 1998
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1998.tb02485.x
Subject(s) - partial pressure , analytical chemistry (journal) , oxygen , solubility , phase (matter) , atmospheric temperature range , chemistry , mineralogy , materials science , thermodynamics , environmental chemistry , physics , organic chemistry
The phase equilibria near (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10+delta ((Bi,Pb)‐2223) was studied in the temperature range of 750°‐820°C in air and in reducing atmospheres. In air, (Bi,Pb)‐2223 was in equilibrium with one or more of the following phases: (Bi,Pb) 2 Sr 2 CaCu 2 O 8+delta ((Bi,Pb)‐2212), (Sr,Ca) 14 Cu 24 O 41 (14:24), (Ca,Sr) 2 CuO 3 , (Bi,Pb) 4 (Sr,Ca) 5 ‐CuO x (451), Ca 2 PbO 4 , and CuO. Ca 2 PbO 4 and the 451 phase were not in equilibrium with (Bi,Pb)‐2223 at an oxygen partial pressure ( p O2 ) of 10 ‐3 atm, which is indicative of higher lead solubility in (Bi,Pb)‐2223 under more‐reducing conditions. In a second set of experiments, the lead content in both (Bi,Pb)‐2212 single crystals and (Bi,Pb)‐2223 powders was investigated as a function of p O2 at a constant temperature of 750°C. Lead solubility in (Bi,Pb)‐2212 and (Bi,Pb)‐2223 increased as p O2 decreased.