Texture development in Bi-based superconductors grown in high magnetic fields and its effect on transformation of Bi(Pb)2212 to Bi(Pb)2223

Ag-doped Bi2212 bulks with a magnetization anisotropy factor at 5 K as high as 6.5 have been obtained by magnetic melt processing (MMP) in a magnetic field of 13 T, which shows that high magnetic fields are of great importance to achieve extremely high texture in Bi2212 bulks. Some texture is also introduced in Bi(Pb)2212-based bulks by MMP. This texture can result in a texture development in the Bi(Pb)2223 phase when most Bi(Pb)2212 is transformed into Bi(Pb)2223 using a long sintering time, which suggests that there is a correlation between the grain alignment of Bi(Pb)2223 and its precursor Bi(Pb)2212. The atmosphere of 1% O-2 + Ar is found especially useful for MMP of Bi(Pb)2212-based bulks from which Bi(Pb)2223 of high content can be formed. (C) 2001 Elsevier Science B.V. All rights reserved.