Microstructures and properties of Bi2212/Ag tapes grown in high magnetic fields

A comparison experiment has been carried out to study the effect of magnetic melt processing (MMP) on fabrication of Bi2212 tapes with reasonable thickness. Vertical magnetic fields up to 10 T were applied during the melt-processing of dip-coated monolayer Bi2212/Ag tapes (over 60 mu m in thickness) which were set horizontally and vertically, respectively. It is found that in the horizontally set tapes the texture development has been obviously enhanced and the transport current density J(c), increases dramatically with the magnetic field strength H-a, up to 7.5 T. When H-a, increases from 7.5 to 10 T, however, J(c), decreases sharply and the reason is still unclear. The magnetic fields have quite different effects on the vertically set tapes and an interference between the Bi2212-silver interface effect and the magnetic field effect on texture development can be detected. These results show that MMP is effective to enhance the texture development in monolayer Bi2212/Ag tape with reasonable thickness and can be applied in its fabrication. (C) 1999 Elsevier Science B.V. All rights reserved.