Submicron TiO2ZrO2 powders produced by vapor phase reaction of TiCl4ZrCl4O2 system

Submicron TiO₂ZrO₂ powders were prepared by the vapor phase reaction of the TiCl₄ZrCl₄O₂ system. The phases appeared were TiO₂ss, ZrO₂ss and ZrTiO₄ss. The major crystal forms of TiO₂ and ZrO₂ were rutile and tetragonal system, respectively. Pure TiO₂ was predominantly anatase and consisted of single crystalline particles with square and plate-like shape. As ZrCl₄ concentration increased, the particle size decreased, the content and lattice constants of rutile increased and particles became polycrystalline. The compound ZrTiO₄ was formed most abundantly as the ratio ZrCl₄/TiCl₄ approached 1 and the effective reaction temperature was raised. It was found that TiCl₄ accelerates the oxidation of ZrCl₄ and ZrCl₄ retards that of TiCl₄ in the vapor phase reaction of the TiCl₄ZrCl₄O₂ system. It was concluded that the formation process of TiO₂ZrO₂ particles consists of the preferential nucleatoin of TiO₂ and the growth by codeposition of TiO₂ and ZrO₂.