Navegando por Autor "Gonçalves, Tássia de Souza"

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    Caracterização estrutural e espectroscópica de vidros fluorofosfatos dopados e co-dopados com Er3+ e Yb3+
    (Biblioteca Digital de Teses e Dissertações da USP, 2017-11-15) Gonçalves, Tássia de Souza
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    Rare earth doped fluorophosphate glass and glass-ceramics: structure-property relations
    (2018-11-01) Gonçalves, Tássia de Souza
    Rare earth RE3+ doped fluorophosphates glasses and glass ceramics are among the most promising candidates for high efficiency laser generation in the near-infrared spectral region. Glass ceramics are polycrystalline materials of fine microstructure that are produced by the controlled crystallization (devitrification) of a glass. By developing fluorophosphate base glasses with appropriate compositions and by controlling crystal nucleation and growth in them, glass ceramics with special properties can be fabricated combining the advantages of fluorides (low phonon energy, low refractive indexes, extensive optical window, lower hygroscopicity) and oxides (high chemical and mechanical stability and high dopant solubility), resulting in enhancement of the RE3+ emissive properties. In this study, we present the synthesis by melting/quenting and structural/spectroscopic investigation of new glasses and glass ceramics with composition 25BaF225SrF2(30-x)Al(PO3)3xAlF3(20-z)YF3: zREF3, where x = 15, 20 or 25, RE = Er3+ an/or Yb3+ and Nd3+. A detailed structural investigation of a series of this glasses has been conducted, using Raman, solid-state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopies.