Synthesis and characterization of Eu3+ and Er3+ doped SiO2-ZrO2 based transparent glass ceramic nanocomposites via sol-gel process / Síntese e caracterização de nanocompósitos vitrocerâmicos transparentes a base de SiO2-ZrO2 dopados com íons Eu3+ e Er3+ via processo sol-gel

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The preparation of transparent glass-ceramic based on the SiO2-ZrO2 doped with Eu3+ and Er3+ ions by the sol-gel methodology was the aim of this work. The structural and optical properties of the systems as a function of the time and temperature of annealing and also zirconium concentration are presented. The sol was prepared in acid solution and left in rest until total evaporation solvent, to obtaining the amorphous monoliths. The follow, the growthing of ZrO2 nanoparticles were induced and by the Transmission Electron Microscopy sizes between 3.1 and 5.5 nm were observed to be dependent to the time and temperature of annealing. The densification from the annealing at 900, 1000 and 1100ºC initially takes the formation of the tetragonal phase of ZrO2, and after 20 mol% of zirconium oxide is observed a mixture of phases between the tetragonal and monoclinic phase, result this evidenced by Raman spectroscopy. In this work the Eu3+ ion was used as a structural and possible luminescent material in the red region, displaying a life time value between 1.4 - 2.3 ms, for samples contend 0.3 mol% of Eu3+. The life time values increases as a function of time and temperature of annealing due the increase of the crystallinity of material that decreases the sites number of Eu3+ ions on the system. The Er3+ ions emission assigned to 4I13/2 4I15/2 localized around 1532 nm, showed a full width half maximum between 29 and 56 nm. The lifetime measurements were realized for Er3+ ions. The larger values of lifetime obtained are correspondent to samples with less crystalinity. Samples annealed in less temperatures show 5.3 ms of lifetime while samples annealed in higher temperatures show 6.5 ms of lifetime.

ASSUNTO(S)

europium glass ceramic lanthanide sílica silica európio lantanídeos sol-gel erbium luminescência óxido de zircônio luminescence vitrocerâmica cristalização sol-gel crystallization érbio zirconium oxide nanocomposite nanocompósito

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