From amorphous phase separations to nanostructured materials in sol–gel derived ZrO2:Eu3+/SiO2 and ZnO/SiO2 composites

ZrO2:Eu3+–SiO2 and ZnO–SiO2 composites have been synthesized by a sol–gel method by using a specific gelation and drying procedure. In the two cases we were able to produce large and transparent monolithic samples. Microstructural properties of these materials were investigated by thermo-differential and thermo-gravimetric analysis, X-ray diffraction, transmission electron microscopy and small angle X-ray scattering. The existence of a miscibility gap in both systems results in the formation of nanocomposites where crystallized zirconia or amorphous zinc oxide nanoparticles are dispersed in a silica glass matrix. These two kinds of nanocomposites are potential high efficiency luminescent materials because the nanoparticles size is easily controlled by the annealing conditions.