de Assumpcao, T. A. A.da Silva, D. M.Kassab, L. R P [UNESP]Martinelli, J. R.de Araujo, C. B.2014-05-202014-05-202010-10-01Journal of Non-crystalline Solids. Amsterdam: Elsevier B.V., v. 356, n. 44-49, p. 2465-2467, 2010.0022-3093http://hdl.handle.net/11449/41661The influence of the temperature on the nucleation of silver nanoparticles (NPs) in Tm3+/Yb3+ codoped PbO-GeO2 glasses was studied in this work. The infrared-to-visible frequency upconversion (UC) luminescence of Tm3+ ions was used to probe the NPs nucleation and the results were correlated with the increase of the heat-treatment temperature. Emission spectra in the blue-red region were measured by exciting the samples with a cw 980 nm diode laser in resonance with the Yb3+ transition (F-2(7/2) -> F-2(5/2)). The results were correlated with transmission electron microscopy measurements and revealed the different behavior of the nucleation process as a function of temperature.The enhanced UC emission in the visible region is attributed to the increased local field in the proximity of the silver NPs combined with the Yb3+ -> Tm3+ energy transfer. (C) 2010 Elsevier B.V. All rights reserved.2465-2467engNanoparticlesUpconversionLead germanate glassArtigo10.1016/j.jnoncrysol.2010.02.016WOS:000285282100037Acesso restrito