Discommensuration Structure of Mass Density Waves in Higher Stage Graphite Intercalated Compounds

A thermodynamical treatment has been developed in order to elucidate the phase transition mechanism of higher stage alkalimetal graphite intercalated compounds. In particular, the properties of discommensurations or domain-like structure associated with the mass density waves of alkali-metals have been investigated. Both the shape and the size of the calculated domain structure are in good agreement with the observed results on C 24 Rb and C 24 Cs. Possibility of stacking ordering of discommensurations along the c -direction in lower temperatures is also discussed.