Uso da luminescência do Eu3+ no estudo da vizinhança local e da transferência de energia Y B3+

• Ano de defesa: 2010
• Autor(a) principal: Amaral, Dayanne Fernandes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Programa de Pós-graduação em Física; Física
• Palavras-chave em Português: Terra rara; Espectroscopia; Luminescência; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://app.uff.br/riuff/handle/1/19117

This work consists basically of two parts. The first envolves the study of the optical properties of dielectric nanocrystals Y2O3, Al2O3, Y2SiO5 and Gd2SiO5 doped with rare earth trivalent ion, europium (Eu3+), prepared by the combustion synthesis method. Luminescence spectra of these samples shows well defined peaks that reveals information about the local neighborhood of the doping ion and allows the calculation of Judd-Ofelt parameters not yet found in the literature for Y2SiO5 and Gd2SiO5 matrices. The second part is devoted to observing and analyzing the effect of cooperative energy upconversion in samples of Y2SiO5 codoped with trivalent ytterbium (Y b3+) and Eu3+ in different concentrations, a mechanism purely dependent on the concentration of Y b3+ and Eu3+. The dynamics of the luminescence of these samples were recorded and the energy transfer rate between pairs of Y b3+ and Eu3+, used as a fitting parameter in a system of coupled rate equations, was estimated for samples with different concentrations.