Electronic structure studies of high-Tc superconductors by high-energy spectroscopies

A review of our high-energy spectroscopy studies of the electronic structure of the new high-T
c
superconductors is given. X-ray-induced photoelectron spectroscopy, bremsstrahlung-isochromat spectroscopy, Auger electron spectroscopy, and electron energy-loss spectroscopy have been used. Parameters determining the correlated electronic structure have been derived, together with information on the nature and the symmetry of the charge carriers.