Abstract:
The monoclinic (space group C2/m) superstructure of V14O6, which is formed in the atom-vacancy ordering of the tetragonal solid solution of oxygen in vanadium, is studied by the methods of x-ray diffraction and symmetry analysis. It has been found that the channel of the order-disorder phase transition attributed to the formation of the monoclinic suboxide V14O6 includes six superstructure vectors belonging to three non-Lifshitz stars {k1−1}, {k1−2}, and {k1–3} of one type {k1}. The distribution function of the O atoms in the V14O6 monoclinic superstructure has been calculated. It has been shown that the displacements of V atoms distort the body-centered tetragonal metal sublattice, thus preparing the formation of the fcc sublattice and the transition from the suboxide V14O6 to the cubic vanadium monoxide with the B1 structure.
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