X-ray absorption study of oxygen in the high-Tc superconductor Bi2Sr2CaCu2O8 near the interfaces to Cu, Ag and Au
The influence on O 2p holes in single crystalline Bi2Sr2CaCu2O8 upon the interface formation to Cu, Ag and Au has been studied by O K edge X-ray absorption measurements. It was found that Cu reduces the amount of doping induced O 2p holes significantly in the vicinity of the interface, whereas Ag and Au gave a much smaller reduction of these states. Photoemission spectra confirmed previous finding