Photoemission electronic states of thallium- and bismuth-based superconductors

X-ray photoemission spectra the core-levels as well as the X-ray photoemission spectra and ultraviolet photoemission spectra from the Valence bands of the (Tl0.6Pb0.5)(ST0.9 Ba-0.1)Ca2Cu3Oy and (Bi1.75Pb0.35)Sr1.9Ca2.05CU3.05Oy superconductors were measured and analyzed. Special attention was paid to the valence band X-ray photoemission spectra and ultraviolet photoemission spectra, the Cu 2p core-level X-ray photoemission spectra and the Cu L-2,L-3-M4,5M4,5 and O K-L2,3L2,3 Auger spectra. Both Cu 2p(3/2) and Cu 2p(1/2) core-level lines consisted of two spin-orbit split main lines accompanied with the two satellite lines. The charge transfer energy Delta from the oxygen ligand to the copper 3d(9) states and the hopping integral t were estimated from the energy separation between the main line and the satellite line taking advantage of the local cluster model calculations and their extension to high-temperature superconductors. The Coulomb correlation on-site energy U-dd of two electrons in the same copper orbital and U-pp Of two electrons in the oxygen orbital as well as the correlation energy U-cd of the 2p core hole - 3d electron interaction have been estimated from the Auger electron spectra and the valence band spectra. They are: U-dd = 6.0 +/- 0.5 eV, of U-pp congruent to 10 +/- 1 eV and of U-cd congruent to 8.0 +/- 0.5 eV nearly the same for both the Tl- and Bi-compounds. We conclude that these compounds are the charge transfer strongly-correlated metals.