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 radiat ion and were deposited sonochemically on microspherical alumina particles. In a different sonochemical reaction Eu2O3 and Tb2O3 were doped into nanoph ased alumina particles. For both systems the decay times of the fluorescenc e was measured. The luminescence of the alumina substrate was found to be m uch shorter than that of the rare-earth oxides. Differences between the dec ay times of the deposited and doped materials are accounted for by the stro nger guest-host interaction and absence of concentration quenching in the d oped material. (C) 2000 American Institute of Physics. [S0003-6951(00)04733 -1].