Solid solutions of Si2O3 in mullite

An explanation is proposed for the possibility of the formation of solid solutions of silicon oxide in mullite. The difference in the diffusion coefficients of cations in complex oxides during their synthesis leads to the formation of a solid solution of an oxide containing a cation with a lower diffusion coefficient in a complex oxide and a phase consisting of an oxide containing a cation with a high diffusion coefficient or enriched in this oxide. Using additives of yttrium or scandium oxides, which are chemisorbed onto the aerosil surface (source of SiO ₂ ), it is possible to make the rate of diffusion mass transfer of aluminum cations higher than that of silicon cations, and to obtain a solid solution of silicon oxide in mullite. Il. 2, bibliography: 10 titles.