A STUDY OF OPTICAL-ABSORPTION OF THIN AMORPHOUS CEO2-TEO2 FILMS

Optical absorption in the wavelength range 300 to 800 nm is studied in CeO2-TeO2 amorphous films prepared by a co-evaporation process. The f undamental optical absorption edge is sharp, resembling that found in crystalline rather than amorphous materials-as has been previously rep orted for CeO2 and CeO2/SiO filMS (Al-Dhhan and Hogarth 1986). The opt ical gap generally decreases as the proportion of CeO2 in the mixed fi lms is increased, but for the sample with less than 10wt% TeO2 the opt ical gap is higher than for the CeO2 filM.