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XAS investigations of Eu-doped BaAl2O4. Part 2: EXAFS experiments

Nanocrystalline sample of pure BaAl2O4 and one doped with 4.9 at% Eu in relation to barium were prepared by a hydrothermal method. Both samples were characterized by synchrotron based X-ray absorption spectroscopy. The EXAFS experiments at the Ba (5247 eV) and Eu (6977 eV) L3-edges have been performed in order to study the local environment of the Eu3+ dopant in detail. In the fitting procedure of EXAFS data at the Ba L3‐ edge, fits comprising two oxygen nearest neighbour shells with 6 oxygen atoms at about 2.7 Å and 3 oxygen atoms at about 2.95 Å, and 3 aluminium atoms at 3.4 Å and 3.5 Å fit the experimental data well for both the pure BaAl2O4 and BaAl2O4 doped with 4.9 at% Eu. The results revealed that the local structure of the pristine BaAl2O4 with 9 oxygen atoms in the first coordination sphere is retained during Eu‐doping. The obtained radial distribution functions for the Eu-doped sample obtained at the Ba L3-edge and at the Eu L3-edge are quite similar, which indicated that the short range order structure around Ba and Eu are very similar. The EXAFS data also showed that no substantial amounts of Eu2O3 and AlEuO3 were present in the Eu-doped sample.

Barium aluminate ; Europium doping ; X-ray absorption spectroscopy ; EXAFS

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