High quality sol-gel thin films: Elaboration, studies in waveguiding configuration and application to sol gel scintillators

The sol gel process is a rather simple route for the elaboration of pure or doped well known oxides such as TiO₂ ZrO₂... or less usual oxides such as Lu₂O₃, Gd₂O₃... in thin film form. A proof of the high optical quality of the layers is their ability to propagate light even if their application is not in the waveguide field. Moreover waveguiding properties of the layers allow their studies in waveguiding configuration. Among these methods, the most attractive for the sol gel films is the very low frequency waveguide Raman which provides the nanocrystals sizes and phases according to the annealing temperatures as illustrated by ZrO₂ sol gel layers studies. For such measurements the thin films must be very carefully elaborated as described in this presentation. As example of application, Gd₂O₃ sol gel scintillating films are presented, when studied in waveguiding configuration and used in transmission configuration. The sol elaboration is described. The thickness and the refractive index of the films are analysed as a function of the annealing treatment. Results of the europium doped gadolinium oxide layer under X rays excitation are presented which underlined the attention paid on all the steps of elaboration procedure.