Formation of, and ion-transport in, low-dimensional crystallites in carbon nanotubes

The formation of low-dimensional crystal structures, obtained by filling carbon nanotubes from the molten salts, is considered for three stoichiometries (the MX, MX2 and MX3). For the MX stoichiometry, general classes of inorganic nanotube (INT) are predicted to exist whose morphology depends both on the low-energy (bulk) crystal structure and the encasing carbon nanotube diameter. These INTs are generally found to have no direct bulk analogues. For both the MX2 and MX3 stoichiometries crystal structures are predicted which either have a direct bulk analogue, or whose structure can be considered as a distortion of a bulk fragment. In both of these stoichiometries unusual (high anion coordination) crystallites are predicted. For the MX stoichiometry the ion transport mechanism is investigated and discussed, whilst for the MX3 the vibrational densities of states are analysed with respect to both the pure liquid and idealized crystallites.