LOW-TEMPERATURE FORMATION MECHANISM OF DOUBLE OXIDES FEXZR(TI)(1-0.75X)O-2-DELTA PREPARED FROM ALKOXIDES AND ACETYLACETONATES

As a result of titanium and zirconium alcoholates hydrolysis in the pr esence of dissolved Fe(acac)(3), amorphous iron-containing gels have b een synthesized. Their heat treatment has led to polycrystalline doubl e oxides FexZr1-0.75xO2-delta(C) and FexTi1-0.75xO2-delta (T) formatio n. It has been shown that oxides (C) and (T) are likely to be solid so lutions with 0.01 < x < 0.17 and 0.01 < x < 0.14, respectively. On the basis of X-ray diffraction and extended X-ray absorption fine structu re data, iron-zirconium and iron-titanium crystallite models for gels and oxides have been proposed. It has been found that the crystallizat ion process does not lead to a significant change in interatomic dista nces typical for local structures detected in gels.