LETTER TO THE EDITOR Pressure enhancement of the electrical conductivity of graphite intercalation compounds?

Abstract. A novel approach to achieve high electrical conductivity in graphite intercalation compounds is suggested. It is based on a recently observed pressure-induced staging tran-sition in GICS which leads to a higher areal density of the intercalant while the quasi-2D character of the structure, believed to exhibit lower carrier scattering, is still preserved. Research into the structure and properties of graphite intercalation compounds (GICS) is currently one of the most spectacular growth areas of materials science. A fundamental feature of the GICS is the formation of ordered sequences (‘stages’) of graphite and intercalant layers (Rudorff and Schulze 1954). Thus a stage n compound is one where n layers of carbon atoms are interposed between every pair of intercalant layers. Within each layer the carbon atoms form a hexagonal network with a strong covalent-type C-C bond. The stack of layers, however, is held together through a weak van der Waals type of bond and even large molecular species can be intercalated (Fischer 1980). Although the details concerning the staging mechanisms are still a contentious issue (Salzano and Aronson 1965, Safran and Hamann 1979), the prime reason why the intercalation process works so well in graphite is its high degree of structural anisotropy