ELECTRONIC PROPERTIES OF GRAPHITE INTERCALATION COMPOUNDS.

New preparation techniques for Li- and the high stages of the heavy Alkali Graphite Intercalation Compounds (AGIC's) were developed. A new electrochromic effect based on electrochemical intercalation of graphite electrodes was discovered. Electron spectroscopy studies such as XPS, UPS and AES on AGIC's revealed a drastic increase of the density of states and alkali-like s-type conduction bands at the Fermi energy. The shift at E//F appears to be almost independent of the intercalant concentration. From optical reflectivity experiments we observe interband transitions to disappear with the ordering of the intercalant layer. The resistivity and magnetic susceptibility measurements indicate no significant different between a dilute and a concentrated regime.