INFLUENCE OF THE INITIAL CONDITIONS ON CRYSTAL-GROWTH OF THE BI2SR2CACU2OY SUPERCONDUCTOR

Bi2Sr2CaCu2O8 crystal growth has been made by slow cooling of samples, completely or partially melted in gold crucibles. All 2212 growth exp eriments have been made under air atmosphere, using presynthetized cer amics as starting materials. A study carried out from Bi2Sr2CaCu2O8 st oichiometric composition had made possible an optimization of a number of thermal cycle parameters. In a second step, the influence of a var iation in Bi or Bi and Cu stoichiometry in the starting product has be en studied. High-quality 1 x 0.5 mm(2)-large and 10-20 mu m-thick Bi2S r2CaCu2O8 single crystals were grown from the 2212 starting compositio n with Bi2CuO4 flux. Crystals were characterized by X-ray diffraction, scanning electronic microscopy and electrical resistivity. (C) 1997 E lsevier Science Ltd.