Inverse photoemission spectroscopy has been performed on LaSrCuO, YBaCuO, and BiSrCaCuO to study the electronic structure of unoccupied region. It was found that the spectrum of Bi2Sr2CaCu2O8 has a clear Fermi edge, thereby giving a direct evidence for the existence of a Fermi surface (Fermi-liquid states), while those of YBa2 Cu3O7 and La1·85Sr0·15CuO4 exhibit little intensity at the Fermi level. A remarkable and prompt reduction of the Fermi-edge intensity was observed for the La-system. The reduction and absence of the Fermi-edge structure is ascribed to the surface degradation probably due to desorption of oxygen from the surface.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering