Time-dependence of luminescence of nanoparticles of Eu₂O₃ and Tb₂O₃ deposited on and doped in alumina

Nanoparticles of Eu₂O₃ and Tb₂O₃ have been prepared using ultrasound radiation and were deposited sonochemically on microspherical alumina particles. In a different sonochemical reaction Eu₂O₃ and Tb₂O₃ were doped into nanophased alumina particles. For both systems the decay times of the fluorescence was measured. The luminescence of the alumina substrate was found to be much shorter than that of the rare-earth oxides. Differences between the decay times of the deposited and doped materials are accounted for by the stronger guest-host interaction and absence of concentration quenching in the doped material.