Preparation of Bi2Sr2CaCu2O8+x-matrix composites containing fine strontiumcalcium indate inclusions via glass crystallization

The crystallization of glass with a composition of Bi2Sr2CaCu2O8+x + 0.25Sr (0.6)Ca(0.4)In(2)O(4) was studied in air between 400 and 800 degreesC. Belo w 700 degreesC, crystalline phases were formed in the following sequence: ( Sr,Ca)(0.9)Bi1.1O2.55, Cu2O, Bi-2201, (SrCa)In2O4, (Sr,Ca)(3)Bi2O6, and Bi- 2212. Above 700 degreesC, the predominant phases were Bi-2212 and (SrCa)In2 O4. The introduction of In into Bi-Sr-Ca-Cu-O was shown to reduce the glass -forming capability of this system, without suppressing Bi-2212 formation. The Bi2Sr2CaCu2O8+x + 0.25Sr(0.6)Ca(0.4)In(2)O(4) composites prepared by an nealing the precursor glass contained 0.2- to 0.4-mum inclusions and posses sed enhanced superconducting properties.