• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Doctoral Thesis
DOI
10.11606/T.76.2004.tde-11112013-165012
Document
Author
Full name
Carlos Alberto Carneiro Feitosa
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 2004
Supervisor
Committee
Mastelaro, Valmor Roberto (President)
Mendonça, Cleber Renato
Messaddeq, Younes
Sombra, Antônio Sérgio Bezerra
Zanotto, Edgar Dutra
Title in Portuguese
Síntese,cristalização e caracterização de vidros do sistema TiO2-BaO-B2O3
Keywords in Portuguese
Caracterização
Devitrificação
Fase Beta-BaB2O4
Sistema vítreo BaO-B2O3-TiO2
Abstract in Portuguese
Este trabalho teve como principal objetivo o estudo sistemático da obtenção da fase beta-BaB204 (beta-BBO) a partir de uma fase vítrea do sistema BaO-B2O3-TiO2. Foram estudadas amostras contendo entre 4 e 16% de TiO2. A avaliação das propriedades térmicas, estruturais e microestruturais das amostras foi realizada empregando as técnicas de Analise Térmica Diferencial (DTA), Difração de Raios-X (DRX), Microscopia óptica (MO), Microscopia Eletrônica de Varredura (MEV), Espectroscopia Raman, Absorção e Transmissão óptica no Infravermelho, Espectroscopia de Absorção de Raios-X (XAS) e Ressonância Magnética Nuclear (RMN). O coeficiente de Geração de Segundo Harmônico (GSH) foi obtido através das medidas do loci de casamento de fase e da Franja de Maker. O estudo do processo de cristalização revelou que em todas as amostras prevaleceu o mecanismo de cristalização superficial. Nas amostras contendo 4 e 8% de TiO2 foi observada a cristalização da fase beta-BBO enquanto que nas amostras contendo 15 e 16% de TiO2, foi observado que o processo de cristalização se inicia pela fase BaTi(BO3)2 e que somente após longos tempos de tratamento, a fase beta-BBO se toma a fase predominante. A identificação da fase BaTi(BO3) somente foi possível com a utilização da técnica de Espectroscopia Raman. O estudo da estrutura local através das técnicas de XAS e RMN mostrou que a estrutura local ao redor dos átomos de titânio, bário e boro nas amostras cristalizadas é pouco afetada quando a quantidade de TiO2 passa de 4 para 16%. A análise dos resultados da medida de geração de segundo harmônico mostrou que nas amostras contendo uma camada da superfície cristalizada, o valor do coeficiente de geração de segundo harmônico (deff) é equivalente ao do quartzo monocristalino e na amostra contendo 16% de TiO2, corresponde a 70% do valor observado na fase beta-BBO em sua forma monocristalina
Title in English
Synthesis, crystallization and characterization of TiO2-BaO-B2O3 glassy system
Keywords in English
BaB2O4 barium borate phase
BaO-B2O3-TiO2 glassy system
Characterization
Devitrification
Abstract in English
This work consists of a systematic study of the beta-BaB2O4 (beta-BBO) crystalline phase obtained from the BaO-B2O3-TiO2 glass system containing amounts of titanium varying from 4 to 16 mol%. The thermal, structural and microstructural properties of the samples were evaluated by the following techniques: Differential Thermal Analysis (DTA), X-Ray Diffraction (XRD), Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Raman Spectroscopy, Infrared Optical Absorption Spectroscopy, X-Ray Absorption Spectroscopy (XAS) and Nuclear Magnetic Resonance (NMR). The Second Harmonic Generation (SHG) coefficient (def) was obtained from the phase matching Loci and Maker fringe curves. A study of the crystallization process revealed that the surface crystallization mechanism predominated in each of the samples. Only the beta-BBO phase was observed in the samples containing 4 and 8 mol% of TiO2. However, in the samples containing 15 and 16 mol% of TiO2, crystallization of the BaTi(BO3)2 occurred first and was followed by crystallization of the P-BBO phase, which subsequently became the main phase as the period of heat treatment increased. The identification of the BaTi(BO3)2 phase in the early stage of the crystallization process was only possible by using the Raman spectroscopy technique. Based on the results obtained from the XAS and NMR techniques, it was found that the increasing the titanium concentration does not affect significantly the short-range order around Ti, Ba and B atoms. An analysis of the SHG data obtained from the crystallized surface of the glassy samples indicated that the SHG coefficient, def, was comparable to that of the z-quartz monocrystalline sample and, in the sample containing 16 mol% of TiO2, it corresponded to 70% of the value observed for the monocrystalline beta-BBO sample
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
CarlosFeitosaD.pdf (7.64 Mbytes)
Publishing Date
2013-11-18
 
WARNING: The material described below relates to works resulting from this thesis or dissertation. The contents of these works are the author's responsibility.
  • FEITOSA, C, et al. Crystallization, texture and second-harmonic generation in TiO2 BaO B2O3 glasses [doi:10.1016/j.optmat.2005.05.003]. Optical Materials (Amsterdam) [online], 2006, vol. 28, nº 8-9, p. 935-943.
  • JACINTO, C, et al. Thermal properties of barium titanium borate glasses measured by thermal lens technique [doi:10.1016/j.jnoncrysol.2006.03.089]. Journal of Non-Crystalline Solids [online], 2006, vol. 352, p. 3577-3581.
  • MASTELARO, VALMOR R, et al. XANES study of titanium environment in BaO-B2O3-TiO2 system [doi:10.1238/Physica.Topical.115a00486]. Physica Scripta. Topical Issues [online], 2005, vol. T115, p. 486-488.
  • MASTELARO, VALMOR R, et al. Short-range structure in BaO-B2O3-TiO2 Glasses analysed by XAS and 11B-NMR. In III International Symposium on Non-Crystalline Solids and VII Brazilian Symposium on Glass and Related Materials, Maringá, 2005. Proceddings of the III International Symposium on Non-Crystalline Solids and VII Brazilian Symposium on Glass and Related Materials., 2005. Resumo.
  • JACINTO, C., et al. Thermal Properties of barium titanium borate glasses by thermal lens technique. In III International Symposium on Non-Crystalline Solids, VII Brazilian Symposium on Glass and related Materials, Foz Do Iguaçu, 2005. Proceedings of III International Symposium on Non-Crystalline Solids, VII Brazilian Symposium on Glass and related Materials., 2005. Abstract.
  • MASTELARO, VALMOR R, et al. Synthesis and characterization of beta-BaB2O4 Glass-Ceramics. In VI Brazilian Symposium on Glass and related Materials and II International symposium on Non-crystalline Solids, Campos do Jordão, 2003. Proceed. of the VI Brazilian Symposium on Glass and related Materials and II International symposium on Non-crystalline Solids.Campos do Jordão, 2005. Abstract.
  • MASTELARO, VALMOR R, et al. XANES study of titanium environment in BaO-B2O3-TiO2 system. In 14a Reunião Annual de Usuários do LNLS, Campinas, 2004. Resumos da 14a Reunião Annual de Usuários do LNLS., 2004. Resumo.
All rights of the thesis/dissertation are from the authors
Centro de Informática de São Carlos
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2021. All rights reserved.