Sonochemical preparation and characterization of Eu2O3 and Tb2O3 doped in and coated on silica and alumina nanoparticles

Submicron size spheres of silica and alumina prepared by well-known methods were coated sonochemically by nanoparticles of oxides of europium and terb ium using the same concentration of ions. We have also used sonochemistry t o prepare nanoparticles of silica and alumina doped by the same rare-earth ions for comparison. The highest luminescence intensities were observed for europium and terbium doped in nanoparticles of alumina of dimension 20-30 nm. The intensities are comparative or higher than in commercial phosphors.