Crystal growth of Bi2Sr2Ca2Cu3O10+x and (Bi,Pb)2Sr2Ca2Cu3O10+x by the KCl flux method

Abstract

Bi2Sr2Ca2Cu3O10+x and (Bi,Pb)2Sr2Ca2Cu3O10+x single crystals with a sharp superconducting transition at Tc = 109 K were grown using a modified KCl flux technique. The crystals show platelike morphology with typical dimensions of 0.5 × 0.5 × 0.002 mm3 and 0.25 × 0.25 × 0.001 mm3 for Pb-free and Pb-doped compositions, respectively. The formation of Bi-2212 intergrowth in the crystals is suppressed by utilization of a stable MgO crucible, suppression of the KCl evaporation, and isothermal heat treatment at a temperature close to the melting temperature of the oxide precursor in the flux. Morphology, phase purity, and chemical composition of grown crystals were determined by various analysis methods while the superconducting properties were studied by magnetization and resistivity measurements.