Growth conditions and characterization of Bi2Sr2CaCu2O8+δ single crystals

We have grown high-quality BiSr2CaCu2O8+delta (Bi-2212) single crystals by a self-flux method without mixing and grinding of reagent-grade Bi2O2, SrCO3, CaCO3, CuO powders, to simplify the growth process of the Bi-2212 single crystals. During the crystal growth process, the pressure was applied using a brick placed on the cap on an alumina crucible. Under a 0.234 N/cm(2) pressure, we obtained high-quality single crystals with the zero superconducting transition temperature T-c,T-zero = 87.6 K in the best sample. The T-c,T-zero values of the Bi-2212 single crystals were greatly affected by the pressure applied to the cap. The observed T-c,T-zero vs. pressure curve was very similar to the T-c vs. delta curve for Bi-2212 single crystals. The result indicates that the applied pressure to the cap may control the oxygen content in the Bi-2212 crystals. (C) 2003 Elsevier B.V. All rights reserved.