Reactivity of FeVO4 towards oxides and pyrovanadates(V) of Co and Ni

A novel Co2FeV3O11 compound was obtained from a solid state reaction. Co2FeV3O11 undergoes a reversible polymorph transition at 770 ± 5°C. It melts congruently at 980 ± 5°C. The indexing results and the calculated unit cell parameters for both polymorphs of Co2FeV3O11 as well as for the previously obtained Ni2FeV3O11 and Ni2FeVO6 compounds are given. The IR spectra of the above-mentioned compounds are presented.