Polarizabilities and local field estimates for ten oxides from refractive-index measurements on doped films

By using accurate prism-coupled optical waveguide refractive-index measurements on cation-doped indium oxide films and a classical polarizability model having adjustable local field weighting factors, estimates have been obtained for the electronic polarizabilities of ten cations and the relative local fields in their respective oxides. Self-consistent results for the ten oxides were obtained for a constant oxygen polarizability of 1.5 (A)(3). The relative local fields were found to be larger at the oxygen than at the cation sites, consistent with the observation that the refractive index is more sensitive to anion than cation changes. The results should be useful for optical applications requiring dopant control of refractive index (e.g., for antireflection coatings and optical waveguides).