Estudo e desenvolvimento de vidros no sistema cálcio borotelurito

• Ano de defesa: 2015
• Autor(a) principal: PAZ, Edson Carvalho da
• Orientador(a): STEIMACHER, Alysson
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Maranhão
• Programa de Pós-Graduação: PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIA DOS MATERIAIS/CCSST
• Departamento: COORDENAÇÃO DO CURSO DE CIÊNCIA E TECNOLOGIA - IMPERATRIZ/CCSST
• País: Brasil
• Palavras-chave em Português: Estrutura do vidro;Propriedades térmicas;Propriedades ópticas e espectroscópicas;Cálcio borotelurito
• Palavras-chave em Inglês: Optical glass;Glass structure;Thermal properties;Optical and spectroscopic properties; Calcium borotellurite
• Área do conhecimento CNPq: Fisica
• Link de acesso: http://tedebc.ufma.br:8080/jspui/handle/tede/1405

In this work glass formation of CaF2-CaO-B2O3-TeO2 system (CBTx), with tellurium oxide concentrations varing from 20 to 50 wt%, was studied. In order to evaluate the glass forming ability of that system, six glass matrix were prepared and characterized to understand the behavior of their physical, thermal, structural, optical and spectroscopic properties. As far we know, this is the first report in the literature about this glass system. The preparation of glasses CBTx system was carried out keeping the Ca/B2O3. The prepared glass samples were characterized by X-ray diffraction (XRD), volumetric density (ρ), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), differential thermal analysis (DTA), specific heat (cp), refractive index (n), electronic polarizability (α), theoretical optical basicity (Λth), optical absorption coefficient (Ae) and band gap optical (Eopt). The results are discussed in terms of tellurium oxide content and structural properties of the glass samples. Density, thermal stability, refractive index, electronic polarizability and theoretical optical basicity values increase with TeO2 content, while transition temperature (Tg), specific heat, optical window and the band gap optical decrease; Raman and FTIR spectroscopy indicated that the network structure of studied glass is formed by BO3, BO4, TeO3, TeO3+1 and TeO4 units. The CBTx system showed a good ability to glass formation, especially the glass matrix of most TeO2 content (CBT50), which proved to be the most suitable for future work doping with rare earth ions and tests as optical amplifier in communication fibers or other photonic devices.