Abstract
The structural phase transition of stage 2 SbCl5-graphite intercalation compound made from a single crystal of Kish graphite has been investigated by the electron diffraction, specific heat and static susceptibility below 300 K. The phase transition can be explained by the presence of two kinds of species for antimony chlorides. One of these species undergoes a commensurate-incommensurate phase transition at Tcu (=230 K) of first order, and above Tcu it forms a discommensuration structure in which the (\sqrt7×\sqrt7)R19.11° superlattice is modulated by the honeycomb domain structure. The other species remains unchanged as the (\sqrt7×\sqrt7)R19.11° structure at least above Tc1 (=210 K). Below Tc1, there appears the glassy phase which is identified as the (\sqrt7×\sqrt7) structure without directional long range order.
