Isolation of the 110 K superconducting phase of Bi-Pb-Sr-Ca-Cu-O compounds

We have prepared 90% single-phase bulk samples of the 110 K superconducting phase of the Bi-Sr-Ca-Cu-O compounds with different Pb amounts. Critical superconducting temperatures (zero resistance) of up to 109 K were measured in the bulk samples. X-ray powder diffraction patterns of the almost isolated 110 K phase are presented. Computer-simulated diffractograms were obtained, which are in general agreement with the measured ones. A discussion of the role of Pb in the stability of the 110 K phase in this compound is presented.