Rietveld refinement study of vanadium distribution in V+4-ZrSiO4 solid solutions obtained from gels

Vanadium-containing zircon gel precursors with nominal compositions V-x-ZrSiO4 with x=0.0, 0.004, 0.01, 0.04 and 0.2 were prepared by a previously reported colloidal sol-gel technique and annealed for 30 h at 1400 degreesC. The Rietveld refinement of the structures by X-ray powder diffraction confirms previous results concerning the limit of solubility of V+4 in the zircon structure. The new finding regarding with the entry of V+4 in the Zr+4 site for zircon doped with high contents of vanadium is in accordance with reported results. (C) 2002 Elsevier Science Ltd. All rights reserved.