High temperature phase equilibria studies in the Bi-Sr-Ca-Cu-O-Ag system

Abstract

A variety of experimental techniques were utilized to examine the high temperature phase equilibria in the Bi-Sr-Ca-Cu-O-Ag systemu Quenching studies were used to determine the b'quid solubility of Ag in the Bi2Sr2CaCu20g (Bi2212) melt and the details of the peritectic decomposition pathway of Bi22I2 as a function on Ag content and oxygen partial pressure (PO2). A liquid immiscibility region between oxide and Ag liquids in the 8-98 at% range was found above 900''C. Two eutectics were found in the Bi2212-Ag pseudobinary. On the oxide rich side, a eutectic exists at approximately 4 at% Ag. On the Ag rich side, a eutectic exists at approximately 98 at% Ag at a temperature of IS'C below the mehing point of pure Ag. Six distinct solid phases were found to be in equilibrium with the partial melt within the Ag content and PO2 range studied. The stability of these solid phases