The hollandite-type phase K1.33Mg3.11Sb4.89O16 has been studied by X-ray and electron diffraction as well as high resolution electron microscopy at 500 kV. This material was found to adopt the tetragonal hollandite structure, space group I4 m, with a = 10.315 (4)Å; c = 3.080 (4) Å. The formation of a 3c body-centered supercell was observed and this was shown to be due to ordering of potassium cations within the tunnel sites. Computer image simulations established that ordering of the tunnel cations alone rather than the octahedrally coordinated framework cations was responsible for superlattice formation. In some crystals the supercell ordering appeared to occur in domains.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry