Phase stability domains of (Bi,Pb)-2223: Data sources, correlation, and assessment

An assessment of the phase stability of lead-doped Bi-2223, (Bi,fb)-2223, a s a function of temperature and partial pressure of oxygen, p(O-2), derived from equilibration and electromotive force studies carried out by numerous groups of investigators is presented. The data obtained from this assessme nt, coupled with additional more recent data from our laboratory, can be us ed to estimate the stability of this promising high-Tc bismuth cuprate syst em in the temperature range From 650 to 870 degreesC and for oxygen partial pressures ranging from 10(-5) to one atm. For oxygen contents above pO(2)= 0.02 atm, the stability boundaries are reasonably well known. For smaller p O(2), discrepancies are found.