Structural phase transitions inSbCl5-intercalated graphite

Abstract

The structural behavior of ${\mathrm{SbCl}}_5$-intercalated graphite has been investigated as a function of temperature and stage with use of x-ray diffuse scattering techniques. We present a global description of the ordering of the intercalant layers and their stacking arrangements, based on the existence of two segregated molecular species, ${\mathrm{SbCl}}_3$ and ${\mathrm{SbCl}}_6$ ${\mathrm{}}^{\mathrm{-}}$. Strong interactions with the graphite host lead to a variety of long-period registered superlattices associated with the separate in-plane ordering of each molecular type. A new explanation for the structural phase transition at T≊230 K is presented in terms of a dipole-dipole coupling of ${\mathrm{SbCl}}_3$ molecules.