Comparison of the scattering properties between TiO ₂ and ITO clusters based on the particle superposition model

Titanium dioxide (TiO ₂ ) and indium tin oxide (ITO) are both widely used as pigments for thermal barrier nanoparticulate coatings. However, their respective complex refractive indices exhibit different features from each other. In this paper, TiO ₂ and ITO sintered clusters with necking-ball structures were generated based on the particle superposition model. The impact of the different incident wavelengths and the ball-necking factor, as well as the refractive index of the ambient medium on their scattering properties, were compared and discussed. The results indicated that because of the distinct spectral characteristics of TiO ₂ and ITO, the discussed factors (especially the ball-necking factor) displayed quite different effects on the locations and deviations of the maximum extinction cross section in comparison. Though the sensitivity of the ball-necking factor for the ITO cluster to the extinction cross section was higher than that of the TiO ₂ cluster, the state of sintering could be probed and assessed by measuring the extinction spectrum for both TiO ₂ and ITO sintered clusters.