Phonon Properties of Graphite Intercalation Compounds

Abstract

Graphite intercalation compounds (GIC’s) exhibit a rich and varied range of vibrational excitations or phonons which have been extensively studied during the past decade and heavily reviewed [1–3]. Several techniques have been employed to ascertain the phonon properties of GIC’s. These include indirect phonon probes such as specific heat measurements [4] and electrical transport studies [5] as well as primary direct probes such as inelastic neutron diffraction [6], Raman scattering [2], optical reflection/absorption [7], and secondary direct probes such as acoustic attenuation measurements [8]. Given the space limitations for this paper, I feel that is appropriate to focus here on the primary direct phonon probes which are the main source of our current understanding of vibrations in GIC’s. The purpose of this paper is to set the groundwork for an understanding of phonons in GIC’s and apprise the reader of some of the latest exciting developments in that field.