Bi-Sr-Ca-Cu-O bulk superconductors with zero resistance above 110 K

Optimized processing to obtain bulk superconductors in Bi-Sr-Ca-Cu-O system with zero resistance above 110 K has been studied. The superconducting path of the high-T/sub c/ phase has been realized in multiphase polycrystalline samples. The resistance of a typical sample reaches zero at 111 K. The usual resistive tail extended to 80 K has been successfully cut off. The importance of the role CuO played in the sintering reactions for the formation of the 110 K phase is discussed on the basis of the results of DTA (differential thermal analysis) and TG experiments.<>