[en] Full text: In this work, the luminescence properties of Eu₂O₃ doped calcium-sodium-borate (CaNaB) glass have been studied, replacing calcium oxide (CaO) and sodium oxide (Na₂O) with strontium oxide (SrO). The samples were prepared by the melt quenching technique, varying the concentration of SrO (0, 5, 10, 15%) in mol, doped with fixed Eu₂O₃ (0,5%). The diffractograms (XRD) confirmed the amorphous nature of the material. The density data showed an increase as CaO and Na₂O were replaced by SrO, while the molar volume decreased in the same proportions. The doped samples showed absorption bands in the ultraviolet region characteristic of Eu³⁺, and the absorption coefficient showed a decrease with the increasing concentration of SrO. The luminescence measurements indicate emission bands characteristic of the Europium and the emission peaks intensity increases with the strontium concentration. The obtained results show that calcium-sodium-borate glasses have a good combination of properties, which makes these glasses potential candidates for use in photonic devices. (author)

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[en] Full text: Tellurium oxide (TeO₂) is a glass forming which requires the addition of other constituents in the production of glass [1] to get better properties. The addition of B₂O₃ to tellurite glasses increase the chemical stability and become better the thermal properties. The boro-tellurite glasses have shown significant potential for applications in microelectronics [2], solid state laser, optical fiber, optical amplifier etc. This class of glass presents good optical, spectroscopic, thermal and mechanical properties [1]. The large range of applications of boro-tellurite glasses, combined with its good properties, were the main factors that motivate the development of this work, which were prepared and characterized different compositions of boro-tellurite glasses in order to investigate their properties and technological potential. The glasses of the CaO-B₂O₃-TeO₂ system were prepared by the conventional melting-quenching technique, with TeO₂ concentration varying from 20 to 50wt%. Raman and UV-Vis spectroscopic, X-ray diffraction, Differential thermal analysis (DTA), refractive index and density measurements were used for initial characterization. The results are discussed as function to the concentration of tellurium oxide. References: [1] M. A. Khaled, H. Elzahedb, S. A. Fayek, M. M. El-ocker. Optical absorption, infrared and differential thermal analysis studies of borotellurite glass containing nickel. Materials Chemktry and Physics. (1994) 329-332. [2] D. Yardimci, M. Çelikbilek, A. E. Ersundu, S. AYDIN. Thermal and microstructural characterization and crystallization kinetic studies in the TeO₂-B₂O₃ system. Elsevier – Materials Chemistry and Physics. 137 (2013) 999-1006. (author)

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[en] Full text: In the last decades, rare-earth (RE) ions doped solid-state materials have become an important class of optical systems due to their applicability as solid-state laser medium, fiber amplifiers, infrared-to-visible up-conversion, phosphors, and field emission displays. The calcium boroaluminate glass (CaBAl) is an important class of optical materials due to the many applications envisaged, including its use as active media for solid state lasers. The CaBAl glasses are materials with a good combination of thermal, mechanical and optical properties that could be exploited in many optical applications, in particular, for the use as laser host materials. The Nd³⁺ ion has been one of the most studied rare earth element and also one of the most efficient candidates for photonic devices. The calcium boroaluminate glass with composition of (25-x)CaO-15Al₂O-50B₂O₃-10CaF₂ -xNd₂O₃, x varying from 0.50 to 5.0wt% were prepared by the conventional melting-quenching technique. In this work will be presented measurements of X-ray patterns, glass transition temperatures (T_g), crystallization temperature (Tx), density, vibrational (Raman) and optical (absorption and emission) spectra. References: [1] WAN, X.; ZHONG, Q.; TIE, S. L.; SHEN, J. Y. Synthesis and luminescence properties of Tb³⁺ activated CaO-Al₂O₃-B₂O₃ glass. Optoelectronics and advanced materials - rapid communications, China, v.5, p.538-544, 31 may. 2001. [2] XIAO, Z.; YAN, L.; ZHU, F.; ZHANG, F.; HUANG, A. Visible Luminescence of Tm³⁺, Er³⁺ and Yb³⁺ in Calcium-Aluminoborate Glasses. Journal of the Korean Physical Society, V. 55, p. 2630-2633, 2009. [3] DIAS, F. R. Preparação e Caracterização de vidros do sistema Nd₂O₃-Al₂O₃-B₂O₃. 2004. 75. Dissertação (Mestrado) - Área de Física Aplicada do Instituto de São Carlos da Universidade de São Paulo. (author)

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