The crystal chemistry of iron (III) monophosphates with mono and divalent metallic cations
نویسندگان
چکیده
As a contribution to the study of alkaline iron (III) monophosphates, we recently investigated the A3PO4-M3(PO4)2FePO4 (A: alkali metal; M: divalent cation) using both the flux method and the solid state reaction. This investigation led to the synthesis and structural characterization of twelve new compounds. Their structural analysis showed them to be constructed by PO4 tetrahedra and FeOx polyhedra (x = 6, 5, 4). The Fe polyhedra are either isolated or forming finite units of corneror edge-sharing, or infinite chains of edge-sharing octahedra. The resulting Fe structural units are linked by the PO4 tetrahedra via corner or edge-sharing, giving rise to mixed covalent frameworks which can be either bior three-dimentionnel. The alkali cations occupy the interlayer space or tunnels and cavities.
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