The fully relativistic real-space scattering cluster coherent-potential approximation is applied to Bi2Sr2CaCu2O8- for 00.5 with respect to each oxygen sublattice and to (Bi1-xPbx)2Sr2CaCu2O8 for 0x0.25. Increasing F was found as the vacancy content increases, while n(F) is decreased by disorder in the O(1) sublattice (Cu-O layers) and increased due to vacancies in the O(2) sublattice (Bi-O layers). As in the Y-Ba-Cu-O system, the effective oxygen-oxygen pair interactions in the Cu-O plane indicate the creation of isolated' Cu ions. By doping' the Bi sublattice with Pb, F drops and n(F) increases. From the effective Bi-Bi pair interactions an (antilikewise) ordering of Bi and Pb atoms can be deduced. Calculated x-ray-emission and uv-photoemission intensities for the nonstoichiometric system are presented.
ASJC Scopus subject areas
- Condensed Matter Physics