Formation of niobium double oxides by the glycothermal method

Thermal reaction of niobium alkoxide in organic media at 300°C yielded amorphous niobia, which maintained a surface area above 130 m²/g after calcination at 500°C. Niobium double oxides (LiNbO₃, Zr₆Nb₂O₁₇, CaNb₂O₆, CrNbO₄, FeNbO₄, ZnNb₂O₆ and R₃NbO₇ (R; rare earth)) were directly obtained by the reaction of niobium alkoxide with the corresponding metal alkoxide, acetate or acetylacetonate in 1,4-butanediol at 300°C. In some cases, amorphous product was obtained; however, double oxides (SrNb₂O₆, Co₄Nb₂O₉, etc.) crystallized from the products at low temperatures.