Effect of Oxygen Content and Sr/Ca Ratio on Superconducting Properties in Bi2Sr2-xCa1+xCu2O8+δ

Abstract
Superconducting properties of the 80 K class superconductor in the Bi-Sr-Ca-Cu-O system were examined from the viewpoints of the oxygen content and the Sr/Ca ratio. The T c of Bi2Sr2CaCu2O8+δ was reduced with decreasing δ. The solid solution region of Bi2Sr2-x Ca1+x Cu2O8+δ was confirmed for x values between -0.25 and 1.0. The T c changed slightly in the solid solution region. The transition to insulator, however, was not observed by changing the oxygen content or the Sr/Ca ratio.