Some features of the structure rearrangement in mixed and binary Zr-Ti sol xerogels.
- Dr. Yury GAPONOV
- Dr. Yury GAPONOV (Department of atmospheric research, Novosibirsk State University, Novosibirsk, Russia)
- Prof. Yoshiyuki AMEMIYA (Department of Advanced Material Science, The University of Tokyo, Kashiwa, Japan)
- Dr. Kazuki ITO (RIKEN Harima Institute, SPring-8 Center, Kouto, Japan)
- Dr. Hironari KAMIKUBO (Graduate School of Materials Science, Nara Institute of Science and Technology, Takayama, Japan)
- Dr. Lembit KARAKCHIEV (ISSCM SB RAS, Novosibirsk, Russia)
- Prof. Nikolai LYAKHOV (ISSCM SB RAS, Novosibirsk, Russia)
Process of gelation and thermal decomposition at different temperatures of the Zr/Ti sol-xerogels, chemically identical but prepared by different methods (mixed and binary), was studied by SAXS/WAXD with the use of SR. Primary particles in mixed and binary Zr/Ti sol-xerogels have different structure. Using the qualitative contrast variation method it was concluded, that primary particle in mixed system consists of Ti nuclear surrounded by Zr atoms in the outer layer of the particle. In contrast, primary particle in binary system consists of Zr nuclear surrounded by Ti atoms in the outer layer of the particle. Multistage thermal decomposition of the Zr/Ti xerogels proceeds through an intermediate phase formation. In the case of the mixed Zr/Ti xerogel the intermediate phase has a distorted (amorphous) structure of anatase (TiO2) which is formed, probably, inside the primary particle of the xerogel. In this case, during the thermal decomposition the interatomic distance in the intermediate phase is similar to the interplane distance of metal planes in final product (crystalline ZrTiO4 powder). In the case of a binary Zr/Ti xerogel, the intermediate phase has an amorphous structure consisting, probably, of the disordered metal atoms (probably, in an oxide state) surrounded by water molecules.