Intercalation Compounds: Covalent and Ionic Approach

Abstract In contrast to amphoteric graphite, layer-type oxides and chalcogenides generally play the role of acceptors in intercalation reactions. Owing to the more ionic character of the M-O bonds, the structural evolution of the oxides may usually be explained on the basis of electrostatic considerations or in terms of cation oxido-reduction. In contrast, for the more covalent chalcogenides, occupancy of energy levels in the band structure by the transferred electrons constitutes a determining factor which strongly influences not only the structural changes but also the physical properties. Similar bonding considerations account for the strong tendency of the oxides to undergo 2D → 3D transformations.