Symmetry of the unoccupied states in Cs graphite intercalation compounds by X-ray absorption

The X-ray photoabsorption spectra of the first three stages of cesium graphite intercalation compounds have been measured at the L absorption edges of Cs, using a linearly polarized synchrotron beam. The results are interpreted based on the self-consistent field energy band calculation for CsC 8. The L I spectra show strong dependence on the polarization angle of the incident radiation. The structures are well correlated with the p x , p y , and p z final states located on Cs sites. In L II and L III spectra the familiar white lines, characteristic of metals, are observed. These are attributed to transitions to unoccupied states with atomic d character at Cs sites. The results also indicate that the charge transfer between Cs and C layers in CsC 8 is nearly unity.