6533b835fe1ef96bd129e959

RESEARCH PRODUCT

Trivalent cation substitution of pulverulent cobalt—iron molybdates Co1 − xFexMoO4

Sylvie BourgeoisBruno DomenichiniS PétignyC. VautreinK. BassetA Steinbrunn

subject

inorganic chemicalsIon exchangeInorganic chemistryIron oxidechemistry.chemical_elementQuaternary compoundMolybdateCondensed Matter Physicschemistry.chemical_compoundchemistrymedicineFerricGeneral Materials ScienceIsostructuralCobaltCobalt oxidemedicine.drug

description

Abstract Different mixed cobalt—iron molybdates Co1 − xFexMoO4 (0 ≤ x ≤ 1) have been prepared by means of a ceramic process. The oxidation of pulverulent samples leads to ferric molybdate Fe2(MoO4)3, spinelle Co3O4 and cobalt molybdate CoMoO4. After a strong grinding which reduces the grain size (about 0.1 μm) and induces crystallographic defects in the grains, the cobalt—iron molybdates can be partially oxidized into cation-deficient phases. This oxidation corresponds to an isostructural substitution of part of the Fe2+ and Co2+ ions by Fe3+ and Co3+ ions and the creation of cation vacancies. The concomitant presence of trivalent cations and associated cation vacancies in the lattice stabilizes the highest-temperature variety of the cobalt or iron molybdates, i.e., the a variety.

https://doi.org/10.1016/s0254-0584(98)00088-1