Determination of the refractive index of TiO2–Y2O3 ceramic composites

Abstract The heat transfer through porous materials is significantly influenced by radiative transfer which is correlated with the complex refractive index of the material and the structure of the ceramic. By changing these two parameters, the infrared-optical properties can be varied in a relatively wide range. Due to the fact that the complex refractive index of composite materials depends on the mixed phases and their mixing ratio, the refractive index often cannot be found in literature but it can be estimated for the given mixture via different model calculations. To verify these theoretical calculations, several samples were prepared so that their refractive index could be determined. In this work, the measured refractive indices of Al 2 O 3 and TiO 2 as well as those of different TiO 2 –Y 2 O 3 composites are presented. These measurements are compared with available literature data and with the data obtained from the model calculations.