Crystal structure of strontium dicobalt iron(III) tris(orthophosphate): SrCo2Fe(PO4)3

Abstract

The title compound, SrCo2Fe(PO4)3, has been synthesized by a solid-state reaction. It crystallizes with the α-CrPO4 type structure. In this structure, all atoms are on special positions of the Imma space group, except for two O atoms which are located on general positions. The three-dimensional network in the crystal structure is made up of two types of layers stacked normal to (100). The first layer is built from two edge-sharing CoO6 octahedra, leading to the formation of Co4O10 dimers that are connected to two PO4 tetrahedra by a common edge and corners. The second layer results from apex-sharing FeO6 octahedra and PO4 tetrahedra, which form linear chains alternating with a zigzag chain of SrII cations. These layers are linked together by common vertices of PO4 tetrahedra and FeO6 octahedra to form an open three-dimensional framework that delimits two types of channels parallel to [100] and [010] where the SrII cations are located. Each SrII cation is surrounded by eight O atoms.