Phosphotellurite glass and glass-ceramics with high TeO2 content: thermal, structural and optical investigations

Reference	Presenter	Authors (Institution)	Abstract
10-045	Danilo Manzani	Manzani, D.(Instituto de Química de São Carlos, Universidade de São Paulo); Fares, H.(Instituto de Química, Universidade Estadual Paulista); Reyna, A.S.(Departamento de Física, Universidade Federal de Pernambuco); Neto, M.L.(Departamento de Física, Universidade Federal de Pernambuco); Bautista, J.E.(Departamento de Física, Universidade Federal de Pernambuco); Nalin, M.(Instituto de Química, Universidade Estadual Paulista); Ribeiro, S.J.(Instituto de Química, Universidade Estadual Paulista); de Araújo, C.B.(Departamento de Física, Universidade Federal de Pernambuco);	Phosphotellurite based glasses have interesting features such as low characteristic temperatures, large glass forming ability, high thermal stability against crystallization and broad transparency window from UV to near-infrared, which makes them promising materials for photonic and optical applications. In this work, phosphotellurite binary glasses were synthesized by the conventional melt-quenching method according to the composition rule (100 – x)TeO2 – xBa(PO3)2, varying x from 1 to 20 mol% in covered gold crucibles under air. Optical, physical and structural properties of the new glass samples were investigated by differential scanning calorimetry, X-ray diffraction, Raman spectroscopy, absorption from UV to NIR, IR transmittance, M-Lines, and nonlinear optical limiting experiments. Transparent glass-ceramics were obtained for phosphotellurite samples containing 1, 2, 4 and 6 mol % of Ba(PO3)2 and the nanocrystallization was investigated through TEM microscopy. Further, Eu3+ has been used as a local structure probe in determining the symmetries of different sites available according to of barium metaphosphate concentrations. Eu3+-doped phosphotellurite samples were investigated by photoluminescence analysis and the Judd-Ofelt intensity parameters were determined and used to calculate radiative lifetimes and stimulated emission cross-sections. The incorporation of Ba(PO3)2 into a TeO2 network drastically increases the thermal stability against devitrification and helps to extend the infrared multiphonon absorption to longer wavelengths. At low Ba(PO3)2 concentration up to 6 mol%, transparent glass-ceramics are obtained. In addition, the dependence of the spectroscopic properties on the samples’ compositions revealed a promisor transparent glass and glass-ceramics for application in photonic technology.
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