Synthesis and structural characterisation of CsCoPO₄-ABW

The cobalt phosphate, CsCoPO4, possessing the zeolite ABW framework topology has been synthesised using a solid state route. Rietveld refinement from powder neutron diffraction data has shown the material to be a direct structural analogue of CsZnPO4 polymorph III. The framework is made up of alternating cobaltate and phosphate tetrahedra sharing vertices with caesium counter cations located in the channels formed. The presence of Co(II) tetrahedra, confirmed by UV visible spectroscopy, is responsible for the intense blue colour of the material. DTA analysis combined with preliminary variable temperature powder X-ray diffraction has shown the presence of a phase transition at approximately 171 °C to an orthorhombic unit cell probably isostructural with CsZnPO4 polymorph II.