Growth of Bi2Sr2CaCu2Oy single crystals by a self-flux method using precursors

We describe the preparation of Bi2Sr2CaCu2Ox (Bi-2212) single crystals by a self-flux method using a SrBiOy precursor and two different forms of Ca-Cu -O precursors. The precursors SrBiOy, Ca-Cu-O(1) and Ca-Cu-O(2) were produc ed by sintering at 800 degrees C, 800-950 degrees C and higher than 950 deg rees C, respectively. We found that using these precursors lowered the grow th temperature necessary to produce large Bi-2212 single crystals by about 100 degrees C as compared with starting without precursors, and that the Bi -2212 single crystals prepared at 940 degrees C showed a critical transitio n temperature of 91K. In addition, the advantages of using the precursor co ntaining Ca2CuOz to that containing CaCu2Ow for crystal growth are given. ( C) 1999 Elsevier Science B.V. All rights reserved.