Thermal and photochemical methods for the preparation of thin films of cermet materials

The synthesis of thin films of Ag-SiO2, Ag-TiO2 and Ag-TiO2-SiO2 cermet materials is described. The preparation method consists in a sol-gel process based in the dip-coating technique to obtain thin films of a composite material containing the oxidized metal and the corresponding ceramic material (TiO2 and/or SiO2). The films, prepared on quartz, were finally heated or irradiated to induce the reduction of the metal and the formation of the cermet materials. An exhaustive characterization of the samples has been carried out by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and Rutherford backscattering. The optical properties of the prepared thin films were determined by UV-VIS absorption spectroscopy and related to the microstructural characteristics of the cermet. Conclusions have been postulated to relate the experimental conditions of the synthesis (thermal or photochemical) to the microstructure and properties of the resulting materials.