The sol gel process typically involves several key steps: 1. Hydrolysis and Condensation: Precursors, usually metal alkoxides or metal chlorides, undergo hydrolysis and condensation reactions to form a colloidal suspension or "sol." 2. Gelation: The sol gradually evolves into a gel-like network containing both a liquid and a solid phase. 3. Aging: The gel is aged to allow further condensation and the growth of the oxide network. 4. Drying: The liquid phase is removed, often resulting in significant shrinkage. 5. Thermal Treatment: The dried gel is subjected to heat treatments to remove organic residues and to crystallize the material into the desired phase.
