Crystals (Aug 2020)

Forbidden Reflections in TeO<sub>2</sub> in the Vicinity of the Te <i>L</i><sub>1</sub> Absorption Edge

  • Elena Ovchinnikova,
  • Dmitri Novikov,
  • Matthias Zschornak,
  • Anton Kulikov,
  • Ksenia Kozlovskaya,
  • Vladimir Dmitrienko,
  • Alexey Oreshko,
  • Alexander Blagov,
  • Enver Mukhamedzhanov,
  • Nikita Marchenkov,
  • Mickhail Borisov,
  • Azat Khadiev,
  • Arsen Petrenko,
  • Yury Pisarevsky

DOI
https://doi.org/10.3390/cryst10090719
Journal volume & issue
Vol. 10, no. 9
p. 719

Abstract

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Examining forbidden reflections provides valuable information on electronic states and the local environment of resonant atoms in crystals. Experimental studies of two forbidden reflections 002 and 100 in TeO2 single crystals were performed at photon energies close to the L1 tellurium absorption edge. It was found that the spectral form corresponding to these two reflections looks almost identical, which is completely unexpected for a highly anisotropic material. Theoretical consideration shows that only one component fxy of the tensor describing dipole-dipole resonance scattering contributes to the 002 reflection, while two components fxy and fxz correspond to the 100 reflection. Numerical calculations show that the latter tensor component is comparable to the first one, but the combination of several geometric factors leads to the fact that its contribution to the spectrum is negligible. This explains the experimentally observed results. The finding shows a way for targeted investigation of single tensor components and makes it possible to compare different spectra and use them the study the physical phenomena in functional materials.

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