Defect structures in the brannerite-type vanadates. VII. Preparation and study of Zn/sub 1-x/O/sub x/V/sub 2-2x/Mo/sub 2x/O/sub 6/ and Zn/sub 1-x-y/O/sub x/Li/sub y/V/sub 2-2x-y/Mo/sub 2x+y/O/sub 6/ solid solutions
ZnV/sub 2/O/sub 6/ and LiVMoO/sub 6/, both of monoclinic brannerite-type structure, display miscibility in the whole range of composition and form the solid solution ZnLi = Zn/sub 1-y/Li/sub y/V/sub 2-y/Mo/sub y/O/sub 6/. ZnLi may be treated as a matrix able to incorporate an excess of Mo/sup 6 +/ ions compensated by the equivalent number of cation vacancies O in the Zn/sup 2 +/ sublattice, which results in the formation of ZnLiO = Zn/sub 1-x-y/O/sub x/Li/sub y/V/sub 2-2x-y/Mo/sub 2x+y/O/sub 6/. At y = O, x/sub max/ = 0.15 and the authors deal with ZnO = Zn/sub 1-x/O/sub x/V/sub 2-2x/Mo/sub 2x/O/sub 6/ (which belongs to the ZnV/sub 2/O/sub 6/-MoO/sub 3/ system); at y = 0.25, x/sub max/ approx. = 0.30, and at higher y, x/sub max/ diminishes again. Phase diagrams of ZnV/sub 2/O/sub 6/-MoO/sub 3/ and ZnV/sub 2/O/sub 6/-LiVMoO/sub 6/-MoO/sub 3/ systems are partly resolved on the basis of differential thermal analysis (DTA) and X-ray phase analysis. Lattice parameters of the above-mentioned solid solutions as a function of composition are determined. The MeV/sub 2/O/sub 6/ lattices are amenable to substitution of Mo/sup 6 +/ for V/sup 5 +/ in a quantity exceeding 50%. Dopant ions of various sizes influence the values of lattice parameters. Parameters a and b are dependent on the Mo/V ratio and practically insensitive to the occupation of the original Me/sup 2 +/ site. Parameter c (or c sin ..beta..) is almost sensitive only to the size of Me/sup 2 +//Li/sup +//phi. Cation vacancies behave as ions of a size smaller than the exhausted cations by at least 0.01 A but rather close to 0.06 A.
- Research Organization:
- Institute of Catalysis and Surface Chemistry, Krakow, Poland
- OSTI ID:
- 5421389
- Journal Information:
- J. Solid State Chem.; (United States), Vol. 71:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LITHIUM OXIDES
CRYSTAL STRUCTURE
PHASE STUDIES
MOLYBDENUM OXIDES
VANADATES
ZINC OXIDES
CATIONS
EXPERIMENTAL DATA
MONOCLINIC LATTICES
SOLID SOLUTIONS
ALKALI METAL COMPOUNDS
CHALCOGENIDES
CHARGED PARTICLES
CRYSTAL LATTICES
DATA
DISPERSIONS
INFORMATION
IONS
LITHIUM COMPOUNDS
MIXTURES
MOLYBDENUM COMPOUNDS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SOLUTIONS
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
ZINC COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies