Formation of nanostructures in Eu3+ doped glass-ceramics: an XAS study

J Phys Condens Matter. 2013 Jan 16;25(2):025303. doi: 10.1088/0953-8984/25/2/025303. Epub 2012 Nov 29.

Abstract

We describe the results of x-ray absorption experiments carried out to deduce structural and chemical information in Eu(3+) doped, transparent, oxyfluoride glass and nanostructured glass-ceramic samples. The spectra were measured at the Pb and Eu-L(III) edges. The Eu environment in the glass samples is observed to be similar to that of EuF(3). Complementary x-ray diffraction experiments show that thermal annealing creates β-PbF(2) type nanocrystals. X-ray absorption indicates that Eu ions act as seeds in the nanocrystal formation. There is evidence of interstitial fluorine atoms around Eu ions as well as Eu dimers. X-ray absorption at the Pb-L(III) edge shows that after the thermal treatment most lead atoms form a PbO amorphous phase and that only 10% of the lead atoms remain available to form β-PbF(2) type nanocrystals. Both x-ray diffraction and absorption point to a high Eu content in the nanocrystals. Our study suggests new approaches to the oxyfluoride glass-ceramic synthesis in order to further improve their properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ceramics / chemistry*
  • Crystallization / methods*
  • Europium / chemistry*
  • Glass / chemistry*
  • Materials Testing
  • Molecular Conformation
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Particle Size
  • Phase Transition
  • X-Ray Absorption Spectroscopy / methods*

Substances

  • Europium