The iron phosphate CaFe3(PO4)3O

Abstract

A new iron phosphate, calcium triiron(III) tris(phosphate) oxide, CaFe3(PO4)3O, has been isolated and shown to exhibit a three-dimensional structure built by FeO6 octahedra, FeO5 trigonal bipyramids and PO4 tetrahedra. The FeOx (x = 5, 6) polyhedra are linked through common corners and edges, forming [Fe6O28]∞ chains with branches running along [010]. Adjacent chains are connected by the phosphate groups via common corners and edges, giving rise to a three-dimensional framework analogous to those of the previously reported SrFe3(PO4)3O and Bi0.4Fe3(PO4)3O structures, in which the Ca2+ cations occupy a single symmetry non-equivalent cavity.