ABSTRACT
More than 7 years have been passed since a bismuth-based high-temperature superconductor, Bi-Sr-Ca-Cu-O (BSCCO), was discovered by one of the editors (H. Maeda) in 1988 as the first superconductor whose Tc exceeded 100 K [1], The discovery was immediately followed by the discovery of a thallium-based superconductor, Tl-Ba-Ca-Cu-O, by Shen and Hermann [2]. The search for materials with the same layer structure resulted in the discovery of a mercury-based superconductor, Hg-Ba-Ca-Cu-O, in 1993 [3] whose Tc ~ 133 K is the highest in all superconductors, and subsequently the discovery of a copper-based superconductor, Cu-Ba-Ca-Cu-O, which could be formed only by highpressure synthesis [4]. Despite the appearance of these new family members, BSCCO has still attracted much interest for researchers from both the scientific and practical points of view.
