Synthese et structure cristalline d'un nouvel oxyde mixte "FeV 3O 8" ( FexV1-xO2; x ⋍ 0.25 )
Abstract
Single crystals of a new oxide "FeV 3O 8" ( FexV1-xO2: x ⋍ 0.25 ) have been synthesized by slowly cooling a melted mixture with the composition, 8VO 2, 3V 2O 5, Fe 2O 3. The chemical formula has been determined by electron microprobe analysis. The compound, isostructural with AlNbO 4 and VO 2( B), has a monoclinic symmetry, space group {C2}/{m}; the unit cell dimensions are a = 12.13Å, b = 3.679 Å, c = 6.547 Å, β = 106.85°. A structural refinement based on single crystal data has been carried out. It gave an R-factor of 1.9%. This refinement indicated that the iron and vanadium cations are partially ordered, although the average cation-oxygen distances for the two six-coordinated cations were exactly the same (1.961 Å). This conjecture was supported by the calculation of the cation valences.
- Publication:
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Journal of Solid State Chemistry France
- Pub Date:
- February 1979
- DOI:
- 10.1016/0022-4596(79)90157-9
- Bibcode:
- 1979JSSCh..27..191M