Study of growth/intergrowth behavior and structural analyses of Bi2Sr2Ca2Cu3O10+δ single crystals

We report the estimated intergrowth concentration of Bi2Sr2CaCu2O8+δ (Bi-2212) layers embedded in Bi2Sr2Ca2Cu3O10+δ (Bi-2223) single crystals grown using the traveling-solvent-floating-zone technique. Possible phase compatibilities in the liquidus region were discussed using the chemical analysis data of the quenched molten zone of real-growth experiments. The growth of Bi-2223 single crystals can be processed in atmosphere with oxygen content of 5, 10 and 20% O2. The content of 2.5% was found to be the lower oxygen limit. X-ray diffractometry was used to reveal the intergrowth behavior. The values of both the 0 0 L peaks shift and width oscillate as a function of the Bragg index. These oscillations are induced by random intergrowth of Bi-2212 layers in the Bi-2223 matrix. The performed calculations, based on the experimentally determined oscillation amplitude in the 1/d vs. L axes, have enabled us to estimate the concentration of the Bi-2212 layers in the Bi-2223 matrix to be about 2%.