Growth of La-doped Bi2Sr2CaCu2Oy single crystals by a self-flux method

We prepared La-doped Bi2Sr2CaCu2Oy (Bi(La)-2212) single crystals by a self- flux method and investigated the effects of La concentrations on their supe rconducting properties. The plate-like single crystal with a size of 6 x 8 mm(2) was obtained by using the starting material of Bi:Sr:La:Ca:Cu = 2:1.9 :0.1:1:2. In addition, the single crystals tended to be large with increasi ng the temperatures for melting. From the results of X-ray diffraction (XRD ) patterns, we found that the La-doped single crystals were Bi-2212 single phase and that the C-axis lattice constant of the single crystals became sh ort with increasing La concentration x in the starting materials of Bi2Sr2- xLaxCaCu2Oy. (C) 2001 Elsevier Science B.V. All rights reserved.