OPTICAL-PROPERTIES OF TIO2, Y2O3 AND CEO2 THIN-FILMS DEPOSITED BY ELECTRON-BEAM EVAPORATION

Thin films of TiO2, Y2O3 and CeO2 have been deposited by reactive electron beam evaporation at different substrate temperatures in the range 20-degrees-C-300-degrees-C. Studies of the optical properties and water absorption show that the films are porous and have a packing density lower than that of the corresponding bulk material. The refractive index of these oxide films obtained when the films were taken out of the chamber was always higher than that obtained in vacuum. All films contain water, the amount of which was estimated using the water absorption band at 2.97 mum. The water-free absorption coefficients at 10 mum were calculated for the three oxides and were in the ranges 1300-1500 cm-1, 450-600 cm-1 and 250-400 cm-1 for TiO2, Y2O3 and CeO2 thin films respectively.