Preparation and Characterization of High-Purity HfTiO4

The double decomposition of hafnium and titanium tetrakis tertiary amyloxides was used to produce high-purity stoichiometric submicron HfTiO₄ powders. The particle size range was 50 to 400 Å. X-ray diffraction of a 1:1 mixture, as-prepared and heated to ～750°C, indicated that the material is 95% orthorhombic HfTiO₄. The TGA, BET, DTA, and high-temperature X-ray analysis of the as-prepared powders are also reported; the ir absorption and reflection frequencies of HfTiO₄ were determined. The homogeneity and stoichiometry of the powder were demonstrated by electron microscopy and wet chemical analysis. Mixed oxides prepared in this manner were sintered in an ambient atmosphere at 1650° to 1700°C for 4 h or Ionger into a body of nearly theoretical density and uniform microstructure.