Síntese e propriedade fotoluminescente do core-shell Ca(1-x)TiO3:Yb(x)@Ca(1-y)TiO3:Er(y)
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Data
2015-02-26
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Universidade Federal de Goiás
Resumo
In recent years, research in the nanocomposites area of core-shell type
increased significantly. The core-shell type nanoparticles with
photoluminescence properties (PL) attract much attention from the scientific
community. Are also of great interest nanoparticles that exhibit the
upconversion energy, i.e. they absorbing low energy photons and emission
high-energy photons. The present work has as objective nanocomposites
synthesis of core-shell type, with CaTiO3 matrix (CT) and doped with rare earth
ions Er3+ and Yb3+ in a variety composition and variations, to analysis the
photoluminescent properties. The nanoparticles of the core and shell were
obtained by the Method of Polymeric Precursors. The samples were
characterized by X-ray diffraction (XRD) for structural characterization, and it
was found that All samples presented the perovskite structure of the
orthorhombic type. The characterization by Transmission Electron Microscopy
(TEM) failed to demonstrate the formation of core-shell, requiring analysis by
Energy Dispersive X-ray (EDX), which showed the presence of rare earth Er3+
and Yb3+ in the different layers. The UV-Vis gap allowed the calculation of the
shell and core samples. The PL emission results were used to relate the
thickness of the shell and the intensity of the emission. On the other hand, to
study the upconversion energy, core materials showed a higher intensity than in
the core-shell; the best intensity in the core-shell was found with doping the
core with Yb3+ and Yb3+ with shell and Er3+ suggesting the transfer of energy
between the layers.
Descrição
Palavras-chave
Core-shell, Método dos precursores poliméricos, Conversão ascendente de energia, Perovsquita, Core-shell, Method of polymeric precursors, Upconversion, Perovskite
Citação
EDUARDO, A. C. Síntese e propriedade fotoluminescente do core-shell Ca(1-x)TiO3:Yb(x)@Ca(1-y)TiO3:Er(y). 2015. 59 f. Dissertação (Mestrado em Química) - Universidade Federal de Goiás, Catalão, 2015.