Surface modification on time-resolved fluorescences of Fe2O3 nanocrystals

The time-resolved studies on the fluorescence properties of Fe2O3 nanoparti cles prepared by forcing hydrolysis and microemulsion techniques were carri ed out for the first. time. Two different systems of different sized nanocr ystals were characterized. Specifically Fe2O3 5, 10 and 20 nm particles in water and Fe2O3 5, 10 nm particles in toluene demonstrated different fluore scence behavior. We discussed the observed phenomena in terms of surface re lated effects, attributing the crucial role in optical time response to the surface polarization in these systems. At the same time we clarify some co ntroversial conclusions made in other related studies. (C) 2000 Elsevier Sc ience Ltd. All rights reserved.