Abstract :
Y1.8Nd0.2O3 and Y1.8Er0.2O3 powder samples were prepared by combustion synthesis. X-ray diffraction showed that the
materials are nanostructured, with average coherence length 5–10 nm. The visible and infrared luminescence spectra of
nanometric cubic Y1.8Nd0.2O3 and Y1.8Er0.2O3 show some important differences from those of the bulk materials. In the
case of Y1.8Er0.2O3, faster relaxation of some excited states occurs, leading to changes in the relative intensities of several
optical transitions. As far as nanostructured Y Nd O is concerned, the 4F ª41.8 0.2 3 3r2 I9r2 transition is characterized by a
perturbed intensity pattern of the Stark components and by an anomalous integrated intensity. Possible explanations for this
behaviour are proposed. q1999 Elsevier Science B.V. All rights reserved.
