Electronic structure of HgBa2CaCu2O6+δ epitaxial films measured by x-ray photoemission

The electronic structure and chemical states of HgBa2CaCu2O6+δ epitaxial films have been studied with x-ray photelectron spectroscopy. Signals from the superconducting phase dominate all the core-level spectra, and a clear Fermi edge is observed in the valence-band region. The Ba, Ca, Cu, and O core levels are similar to those of Tl2Ba2CaCu2O8+δ, but distinct differences are observed in the valence bands which are consistent with differences in the calculated densities of states. © 1995 The American Physical Society.