Properties of the high Tc superconducting phases in the (Pb-Bi)-Sr-Ca-Cu-O family of compounds☆

Abstract We specify several properties of lead-substituted ceramics and single crystals belonging to the Bi-Sr-Ca-Cu-O family of compounds. In the ceramics, preparation conditions are indicated which allow us to obtain a proportion of the order of 50% for the volume of the (2223) phase with zero resistance at 107 K. The X-ray powder signatures of the (2212) and the (2223) phases disclose long-range order for these phases. The effective inclusion of lead in the structure is established. On the basis of X-ray precession camera observations of lead-containing single crystals of the (2212) phase, it is shown that the incommensurate modulation wavevector is also modified by the substitution of lead.