Presentation Information
[9p-PA2-29]Deveropment of a Synthesis Process for Pb Reduction in the Bi-Based High-Temperature Superconductor Bi-2223
〇Yuito Mimura1, Marina Mendoza1, Shinzo Yoshikado1, Kenji Sakai1, Yuki Sato1 (1.Doshisha Univ.)
Keywords:
High-Temperature Superconductor,Bi-2223
The Bi-based oxide superconductor Bi2Sr2Ca2Cu3Oy (Bi-2223) possesses a high superconducting transition temperature (Tc) of approximately 110 K, allowing the superconducting state to be attained under liquid-nitrogen cooling (77 K). Owing to its high critical magnetic field, it is regarded as a promising candidate for power-transmission cables and fusion-reactor applications. In conventional sintering, Pb substitution at the Bi and Sr sites is commonly employed, since in the absence of Pb the stable Bi-2212 phase forms preferentially, rendering the synthesis of Bi-2223 exceedingly difficult. Pb, however, imposes a considerable environmental burden. In the present study, we propose a synthesis process that substantially reduces the Pb content. A Pb-doped bulk (Bi-2223 main phase) and a Pb-free bulk (Bi-2212 main phase) were mixed at a mass ratio of 1:5 and sintered in air, whereby the Pb-doped grains served as templates to replicate the Bi-2223 structure within the Pb-free bulk. X-ray diffraction confirmed that the samples consisted predominantly of Bi-2223, and repeated grinding and sintering enhanced the superconducting properties, demonstrating the effectiveness of the proposed process.