Superconducting Properties of Single-Crystal Bi-Sr-Ca-Cu-O Compounds

Abstract

Single crystals of Bi₄(Sr, Ca)₆Cu₄O_z and Bi₄(Sr, Ca)₄Cu₂O_z were grown from molten Bi₂O₃-SrCO₃-CaCO₃-CuO mixtures. These crystals have similar layered structures. The former crystal exibits superconductivity with Tc above 80K and shows Hc2 anisotropy of the ratio of 40-50 between a-b plane and c axis. The latter crystal shows no superconductivity down to 4.2K.