Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-13T14:46:35.684Z Has data issue: false hasContentIssue false
  • English
  • Français

Structure and Luminescence of Europium-Doped Gadolinia-Based Core/Multi-Shell Scintillation Nanoparticles

Published online by Cambridge University Press:  31 January 2011

Teng-Kuan Tseng ,
Jihun Choi  and
Paul H. Holloway
Teng-Kuan Tseng
Affiliation:
tengkuan.uf@gmail.com, University of Florida, Materials Science and Engineering, Gainesville, Florida, United States
Jihun Choi
Affiliation:
soulove2@ufl.edu, University of Florida, Materials Science and Engineering, Gainesville, Florida, United States
Paul H. Holloway
Affiliation:
pholl@mse.ufl.edu, University of Florida, Materials Science and Engineering, Gainesville, Florida, United States
Get access

Abstract

Scintillating nanoparticles with a SiO2 core and a Gd2O3 shell doped with Eu3+ were synthesized with a sol-gel process. Based on transmission electron microscopy (TEM) data, a ∼13 nm Gd2O3 shell was successfully coated onto ∼220 nm mono-dispersed SiO2 nanocores. Eu3+ ions at concentrations of nominally 5 at% exhibited photoluminescent (PL) emission from the SiO2/Gd2O3 nanoparticles after being calcined at 800 0C for 2 h. The SiO2 remained amorphous after calcining, while the Gd2O3 crystallized to a cubic structure. The PL emission was from the 5D0-7F2 transitions of Eu3+ at 609 and 622 nm. Photoluminescence excitation (PLE) data showed that emission from Eu3+ could result from direct excitation, but was dominated by the oxygen to europium charge-transfer band (CTB) between 250 and 280 nm for Eu3+ doped in Gd2O3. The quantum yield (QY) from thin films drop cast from a mixture of 20 mg of calcined nanoparticles in 500 μL of polymethylmethacrylate (PMMA) and excited in the CTB was 20% for SiO2/Gd2O3:Eu3+ core/shell scintillation nanoparticles. Finally, the above core/shell nanoparticles were passivated with a shell of SiO2 to create e.g. SiO2/Gd2O3:Eu3+/SiO2 nanoparticles. The QYs for this nanostructure were lower than unpassivated nanoparticles which was attributed to a weak CTB for the amorphous SiO2 shell and a higher density of interface quenching sites.

Keywords

core/shellnanostructuresol-gel
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1164: Symposium L – Nuclear Radiation Detection Materials–2009 , 2009 , 1164-L11-01
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Wang, F. Zhang, Y. Fan, X. and Wang, M. Nanotechnology 17, 1527–1532 (2006).Google Scholar
2. Bryan, D. R. G. J. Daniel, in Progress in Inorganic Chemistry, edited by Kenneth, D. K. (2005), p. 47–126.Google Scholar
3. Erwin, S. C. Zu, L. Haftel, M. I. Efros, A. L. Kennedy, T. A. and Norris, D. J. Nature 436, 91 94 (2005).Google Scholar
4. Moszynski, M. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 505, 101–110 (2003).Google Scholar
5. Reiss, M. P. L. L. Peter, Small 5, 154–168 (2009).Google Scholar
6. Gerion, D. Pinaud, F. Williams, S. C. Parak, W. J. Zanchet, D. Weiss, S. and Alivisatos, A. P. Journal of Physical Chemistry B 105, 8861–8871 (2001).Google Scholar
7. Yang, Y. Chen, O. Angerhofer, A. and Cao, Y. C. Journal of the American Chemical Society 130, 15649–15661 (2008).Google Scholar
8. Stober, W, Fink, A and Bohn, E, J. Colloid Interface Sci. 26, 62 (1968)Google Scholar
9. Monkman, A. P. Palsson, L.-O., Advanced Materials 14, 757–758 (2002).Google Scholar