X-RAY-POWDER DIFFRACTION STUDY OF A NEW VANADIUM-OXIDE CR0.11V2O5.16 SYNTHESIZED BY A SOL-GEL PROCESS

The synthesis of the mixed oxide Cr0.11V2O5.16, which presents interes ting electrochemical performances, has been performed from vanadium ox ide gels. Its structure, determined by Rietveld refinement, is similar to that of orthorhombic V2O5, with the formation of CrO6 short chains linking the V2O5 layers. For comparison, the structures of V2O5 (synt hesized by the sol-gel route) and Fe0.11V2O5.16 have been also determi ned by the same method. The position, along the c axis, of the trivale nt ion in the plane formed by the four oxygen atoms of the V2O5 slab, is discussed as a function of the ion size and the crystal field stabi lization energy.