A new Nasicon-type phosphate Co{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3}. 1: Elaboration, optical and magnetic properties

A new cobalt titanium monophosphate has been prepared by low temperature method. It crystallizes with the Nasicon-type structure. The indexation of the X-ray diffraction pattern is consistent with the R{bar 3} or the R32 space groups. The atomic arrangement is a three-dimensional framework formed by PO{sub 4} tetrahedra sharing corners with TiO{sub 6} octahedra. Co{sup 2+} is located in half of the antiprism M(1) sites in a centered (R{bar 3}) or off-centered (R32) position. The optical, EPR and magnetic data can account for a pure ionic Co-O bond.