<i>In</i> <i>situ</i> x-ray investigation of the melting of Bi-Sr-Ca-Cu-O phases

Abstract

High-temperature x-ray studies of the melting of Bi2Sr2Ca1Cu2O8−δ/Ag composites have been undertaken in order to determine the factors that control the melting temperature and the various phases that form during the melt-processing part of the fabrication of these conductors. During the melting process, three distinct phases form and then dissolve in the Bi-rich liquid: first (Sr,Ca)1Cu1O2, then (Sr,Ca)2Cu1O3, and finally (Sr,Ca)O. Ag suppresses the melting point about 30 °C and as much as 10% Ag can dissolve in the Bi-rich liquid. A slight Bi excess also decreases the temperature where the Bi2Sr2Ca1Cu2O8−δ structure disappears and liquid forms.