Bi系高温超伝導線材開発における組織，組成の制御技術

抄録

  Since the discovery of high-T_c cuprate superconductors 30 years ago, their practical applications particularly for saving and storing energy have been expected. However, high-T_c superconducting materials had required very long time before their extensive applications, because of many intrinsic difficulties to achieve enough high critical current performance originated in large anisotropic characteristics, short coherence length and large nonstoichiometry in chemical compositions. Fabrication of polycrystalline superconducting tapes having highly grain-aligned microstructure and well controlled chemical composition is crucially important for deriving potentials of superconductors. Even now, eager efforts have been made to improve synthesis processes for producing long length tapes with high uniformity, high reliability and low cost.

  In this review paper, current status of high-T_c superconducting materials and their practical applications mainly for Bi2223 superconducting tapes are shown after brief introduction of superconductors, metallic superconducting materials and characteristic features of cuprate superconductors.