Nanoparticles of strontium aluminate phosphors co-activated by Eu2+ and Dy3+ have been prepared by heating the precursors obtained from nitrate salt-ammonium acetic-urea-gel combustion process at temperature of 1150 degrees C in a weak reductive atmosphere of thermal carbon. Transmission electron microscope (TEM) images revealed that the hollow nanoparticles of SrAl2O4:Eu2+,Dy3+ were formed below 1150 degrees C, while the needle or rod-shaped particles were formed at 1200 degrees C. The XRD patterns indicated that the resulted SrAl2O4:Eu2+,Dy3+ nanoparticles contained distorted monoclinic lattice. The environment ofrare earth ion in SrAl2O4 lattice was investigated by using Eu3+ as ion probe, and the results indicated that there were two kinds of sites occupied by Eu3+, one was centro-symmetrical environment, while the other not. The luminescence and the afterglow properties of the hollow nanoparticles of SrAl2O4:Eu2+,Dy3+ were also investigated. (C) 2008 Elsevier B.V. All rights reserved.