Reactions of Magnesium and Titanium Alkoxides. Preparation and Characterization of Alkoxy-Derived Magnesium Titanate Powders and Ceramics

The interaction between magnesium and titanium alkoxides is studied in order to chose the best precursors for synthesis of MgTiO3. No reaction between magnesium and titanium methoxides and isopropoxides occurs. The solubility diagrams for Mg(OR)2-Ti(OR)4-ROH, R = Et,-Bu at 20°C are studied. Magnesium ethoxotitanates of variable composition MgnTi4-n (OEt)16-2nċ2nEtOH (n=2.0-0) which are structural analogs of Ti4(OR)16 (R = Me, Et) are isolated. This is a quite unusual example of statistical distribution of heteroatoms in molecular structures of metal alkoxides. Among the systems of metal alkoxides with simple aliphatic radicals only Mg(OBu)2-Ti(OBu)4-BuOH gives a convenient precursor for the synthesis of MgTiO3. A simple scheme of preparation of magnesium titanate from the alkoxide solutions is suggested. The phase purity of MgTiO3 is to a considerable extent dependent on the hydrolysis conditions. The alkoxy-derived magnesium titanate is obtained in the form of a uniform fine powder, it can be sintered into dense ceramics in the temperature range of 1140–1220°C which is 150–200°C lower in comparison with the conventional powders.