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http://hdl.handle.net/10773/6114
Título: | Structural and optical properties on thulium-doped LHPG-grown Ta2O5 fibres |
Autor: | Macatrão, M. Peres, M. Rubinger, C. P. L. Soares, M. J. Costa, L. C. Costa, F. M. Monteiro, T. Franco, N. Alves, E. Saggioro, B. Z. Andreeta, M. R. B. Hernandes, A. C. |
Palavras-chave: | Tantalum pentoxide LHPG-growth Rare earth doping XRD PL |
Data: | Fev-2009 |
Editora: | Elsevier |
Resumo: | Structural, spectroscopic and dielectric properties of thulium-doped laser-heated pedestal Ta2O5 as-grown fibres were studied. Undoped samples grow preferentially with a single crystalline monoclinic structure. The fibre with the lowest thulium content (0.1 at%) also shows predominantly a monoclinic phase and no intra-4f12 Tm3+ recombination was observed. For sample with the highest thulium amount (1.0 at%), the appearance of a dominant triclinic phase as well as intraionic optical activation was observed. The dependence of photoluminescence on excitation energy allows identification of different site locations of Tm3+ ions in the lattice. The absence of recombination between the first and the ground-state multiplets as well as the temperature dependence of the observed transitions was justified by an efficient energy transfer between the Tm3+ ions. Microwave dielectric properties were investigated using the small perturbation theory. At a frequency of 5 GHz, the undoped material exhibits a dielectric permittivity of 21 and for thulium-doped Ta2O5 samples it decreases to 18 for the highest doping concentration. Nevertheless, the dielectric losses maintain a very low value. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/6114 |
DOI: | 10.1016/j.mejo.2008.07.033 |
ISSN: | 0026-2692 |
Aparece nas coleções: | DFis - Artigos I3N-FSCOSD - Artigos |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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MJ.pdf | versão pdf do editor | 687.51 kB | Adobe PDF | Ver/Abrir |
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