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

Abstract

The title compound, SrCo 2 Fe(PO 4 ) 3 , has been synthesized by a solid-state reaction. It crystallizes with the α-CrPO 4 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 CoO 6 octahedra, leading to the formation of Co 2 O 10 dimers that are connected to two PO 4 tetrahedra by a common edge and corners. The second layer results from apex-sharing FeO 6 octahedra and PO 4 tetrahedra, which form linear chains alternating with a zigzag chain of Sr II cations. These layers are linked together by common vertices of PO 4 tetrahedra and FeO 6 octahedra to form an open three-dimensional framework that delimits two types of channels parallel to [100] and [010] where the Sr II cations are located. Each Sr II cation is surrounded by eight O atoms.