| Autor: |
Kiisk, Valter, Šavel, Mari, Reedo, Valter, Lukner, Argo, Sildos, Ilmo |
| Předmět: |
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| Zdroj: |
Physics Procedia; Aug2009, Vol. 2 Issue 2, p527-538, 12p |
| Abstrakt: |
Abstract: We employed a sol-gel route to prepare 1% samarium-doped TiO2 nanopowders. Time-resolved photoluminescence (PL) and Raman characterization was performed. After a thermal treatment the powder crystallized in an anatase phase and revealed intense Sm3+ photoluminescence. The emission spectrum of Sm3+ exposed well-resolved crystal-field splitting enabling monitoring of the changes in the local environment. We thoroughly investigated the influence of the annealing treatment (in air) on Sm emission intensity. Annealing up to 800 ∘C led to a systematic enhancement of Sm emission. Annealing at higher temperatures, however, led to a marked weakening of Sm3+ emission and simultaneous appearance of an emission band near 830 nm. Annealing temperatures as high as 1000 ∘C were needed to induce the phase transition from anatase to rutile. It was possible to use Sm3+ as a structural probe revealinge peculiarities of the phase transition. [Copyright &y& Elsevier] |
| Databáze: |
Supplemental Index |
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