Influence of the temperature of preparation process on refractive index of sol-gel matrices

The preparation of sol-gel materials in the form of bulks and thin films at different temperatures is described. The procedure involves running the reaction at 50°C and 90°C in an open vessel. Such an approach enables acceleration of hydrolysis and condensation reactions. This procedure yields crack-free sol-gel glasses. The changes in refractive index of sol-gel materials were studied by using Pulrich refractometer. The experimental data indicates significant differences in the optical properties of sol-gel glasses, depending on the temperature during the preparation. The samples show normal dispersion, whereas a higher refractive index was stated for films prepared at a higher temperature.