Electronic structure of Bi-Ca-Sr-Cu-O superconductors studied by photoelectron spectroscopy

Abstract
Photoelectron spectroscopy has been used to study the electronic structure of the newly discovered Bi-Ca-Sr-Cu-O superconductors. A clear Fermi edge is observed showing a metallic behavior. The oxygen 1s core level shows only one peak, in contrast to previous results on YBa2Cu3O7δ. We suggest that the Fermi edge observed is mainly due to electrons derived from Bi-O p bands.