Disordered structure of ZrW1.8V0.2O7.9 from a combined X‐ray and neutron powder diffraction study at 530 K

A novel compound, vanadium aliovalent substituted zirconium tungstate, ZrW_1.8V_0.2O_7.9, was prepared with vanadium substituting tungsten rather than the common zirconium substitution. The structure of the high‐temperature phase was refined from combined neutron and X‐ray powder diffraction data gathered at 530 K. This phase is the disordered centric modification (space group Pa) and the average crystal structure is similar to that of β‐ZrW₂O₈. The V atom occupies only a W2 site and charge compensation is achieved through oxygen vacancy, i.e. the oxygen vacancy occurs at only the O4 site. Atom names follow the established scheme; Evans et al. (1996). Chem. Mater. 8 , 2809–2823.]