Wydział Chemii

Anna Dobrowolska

Eugeniusz Zych

2010

Chemistry of Materials

22

4652-4659

10.1021/cm100828v

Naukowa

Angielski

Artykuł

Two series of BaHfO₃ powders activated with Eu³⁺ ions were prepared with a ceramic method. By stoichiometric variations, the dopant was forced to enter either Ba²⁺ or Hf(IV) sites. X-ray diffraction (XRD) analysis proved that Eu³⁺ ions preferred substitution of Hf(IV) in BaHfO₃, while replacement of Ba²⁺ encountered difficulties and led finally to separation of a foreign phase, Eu₂Hf₂O₇. Yet, it was shown that the host always incorporated the activator both into Hf(IV) and Ba²⁺ positions, and the two sites, Eu_Hf^′ and Eu_Ba^•, were spectroscopically characterized. From photoluminescence spectra, it appeared that Eu_Ba^• gave emissions at 573.6, ∼595, and 626.0 nm, while luminescence from Eu_Hf^′ was practically limited to just one line peaking at 595.6 nm. Luminescence and excitation spectra taken under synchrotron radiation showed that energy from the excited host is preferentially transferred to Eu_Hf^′ compared to Eu_Ba^•. At 10K, the latter was not capable of intercepting any energy upon excitation above the fundamental absorption of BaHfO₃, which limited the luminescence in such conditions to a single line peaking at 595.6 nm. Also, under excitation with X-rays, practically only the Eu_Hf^′ was able to produce luminescence.

https://doi.org/10.1021/cm100828v

https://www.acs.org/content/acs/en.html