Synthesis, structure, magnetic, optical and Mössbauer properties of Na2FeSn(PO4)3

The phosphate Na2FeSn(PO4)3, obtained by solid state reaction, was found to be isotypic with Na2CrTi(PO4)3, with space group R-3c and unit cell parameters a = 8.6617(2) Å, c = 22.0161(7) Å, V = 1430.47(5) Å3, Z = 6. The structural parameters refined using Rietveld method showed that the Na+ ions occupy totally the M1 sites and partially the M2 sites and sharing faces with the [Sn/FeO6] octahedra. The presence of the unique valence of ferric iron in the reported phosphate was confirmed using UV–visible diffuse-reflectance spectroscopy, magnetic measurements and Mössbauer spectroscopy.