Surface properties of KOX and CsOX graphite intercalation compounds

Graphite intercalation compounds (GICs) with heavy alkali oxides were studied by X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). It is shown that both Cls and Ols spectra of CsOx GICs are essentially different from that of the oxidized surfaces of Cs GICs. It is found that the surface areas of CsOx GICs are enriched with oxygen due to migration of the oxygen from the bulk. A number of hexagonal and square superlattices were observed in the STM images of CsOx GICs. Square 4×4A2 superlattice was observed at the surface of KOX GICs.