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Luminescence of Europium doped ZrO2 nanopowder
|Donats Millers 1, Krisjanis Smits 1, Larisa Grigorjeva 1, Janusz D. Fidelus 2|
1. Institute of Solid State Physics, University of Latvia, 8 Kengaraga, Riga LV-1063, Latvia
Luminescence of ZrO2:Eu free-standing nanocrystals (nanopowders) containing different concentration of Eu (from 0.1 up to 5% in the raw material for nanocrystal synthesis) was studied. The luminescence was excited by a pulsed laser beam (4.66 eV, 8 ns). The luminescence spectra and decay kinetic were recorded. Eu3+ emission lines within 1.4 and 2,5 eV ("red luminescence") were observed in all samples studied, whereas trace from Eu2+ emission was not found. The intensity of Eu3+ luminescence was higher for samples with larger Eu concentration, however above 1% concentration the intensity of luminescence tend to the saturation. The luminescence decay kinetic shown dependence on Eu3+ concentration also. It was concluded only Eu3+ state was incorporated in ZrO2 and above 1% (in raw material) concentration interaction between Eu3+ ions take place. The luminescence decay kinetic shown more than one decay component indicating that Eu3+ was incorporated in different positions. More appropriate position for Eu3+ is Zr4+ site and the charge compensation by oxygen vacancy take place, since one vacancy serve as charge compensator for two Eu3+ the different spacing between oxygen vacancy and Eu3+ is suggested. Thus, the oxygen surrounding of Eu3+ was not the same for all ions and different distorted sites appear. Possible configurations of Eu3+ sites will be discussed.
Presentation: Poster at E-MRS Fall Meeting 2006, Symposium C, by Donats Millers
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-09 14:47 Revised: 2009-06-07 00:44