Orientational Locking of Incommensurate Lattices in Mental Chloride GICs

Abstract

In the study of the structures of GIC the orientational locking of incommensurate lattices is a challenging problem: Although the incommensurability of the graphite and the intercalate in-plane lattice indicates that host-guest interactions are weaker than the interactions between the intercalate molecules, most of the incommensurate intercalate lattices exhibit a definite rotational orientation δ with regard to the axis of the hexagonal in-plane lattice of graphite [1]. In order to look for the reasons of this astonishingly behaviour we turned to the study of metal di- and trichloride GICs with simple in-plane structures of the intercalate. These structures are shown in Fig. 1. They consist of a double layer of close-packed chlorine atoms. Metal atoms occupy all or two thirds of all octahedral sites of this double layer, leading to stoichiometries MeC1₂ and MeC1₃ resp., for the metal chloride layer.