The effect of starting precursor conditions on the phase formation and transport properties of Bi-2223/Ag tapes

• Published in: Physica. C, Superconductivity Vol. 386; no. 1-4; pp. 186 - 189
• Main Authors: Jiang, C.H., Yoo, J.M., Ko, J.W., Chung, H.S., Wang, Y.Z., Qiao, G.W.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2003
• Subjects: Bi-2223/Ag tapes; Phase formation; Precursor powders; Transport property; 74.25.Fy; 74.60.Ge; 74.60.Jg; Precursor powders; Bi-2223/Ag tapes; Transport property; Phase formation
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/S0921-4534(02)02252-9

Precursor powders were prepared by the spray–drying method and varied in particle size distributions. The effect of starting precursor conditions on the phase formation and transport properties of Bi-2223/Ag tapes has been investigated. The results show that precursors with fine particle sizes (<2 μm in average) lead to a fast formation of 2223 phase at the early stage of sintering and a high conversion rate from precursors to Bi-2223 in fully processed tapes. The core density and grain texture are improved in the tapes made from fine powders, which correspond to the enhanced J c property. I c values, 60 and 62 A (77 K, in self-field), are achieved in short fully reacted tapes with decreasing the particle size of precursors. However, some large alkaline-earth-cuprate particles can also be found in the tape with the highest I c which indicates that the fine powder also triggers the formation of undesired secondary phase. It might be the reason for the rapid drop of J c at magnetic field higher than 0.05 T along H∥ c direction.