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 CsC8. The LI spectra show strong dependence on the polarization angle of the incident radiation. The structures are well correlated with the px, py, and pz final states located on Cs sites. In LII and LIII 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 CsC8 is nearly unity. © 1991.