The iron phosphate NaBaFe2(PO4)3

Abstract

A new iron phosphate, sodium barium diiron tris(phosphate), NaBaFe2(PO4)3, has been synthesized by the flux method and shown to exhibit the well known langbeinite type structure. The Na, Ba and Fe atoms all lie on threefold axes, while the P and O atoms occupy general positions, one of the O atoms being disordered over two positions, with site occupancy factors of ca 0.7 and 0.3. The [Fe2(PO4)3]∞ framework consists of FeO6 octahedra sharing all their corners with the PO4 tetrahedra. The Na+ and Ba2+ cations are almost equally distributed over two distinct cavities, in which they occupy slightly different positions.