Graphitic interlayer states: A carbon K near-edge x-ray-absorption fine-structure study

We have measured the carbon K near-edge x-ray-absorption fine structure of graphite by transmission, electron yield, and fluorescence yield. A rounded and prominent peak is identified in the near-edge spectrum, among the other well-known spectral features. With the aid of a full-potential linearized augmented-plane-wave band calculation, this feature is interpreted as originating from interlayer states in low-symmetry regions of the Brillouin zone. This finding is relevant to interpreting the near-edge structure of graphite intercalation compounds specially of the alkali-metal type.