Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.

Detalhes bibliográficos
Autor(a) principal: Albarici, Viviane Cristina
Data de Publicação: 2004
Tipo de documento: Dissertação
Idioma: por
Título da fonte: Repositório Institucional da UFSCAR
Texto Completo: https://repositorio.ufscar.br/handle/ufscar/6494
Resumo: This work presents a systematic study of the synthesis and characterization of Li2TiSiO5 and Na2TiSiO5 compounds. We studied their structural, morphologic and luminescent properties using X ray diffraction, Raman spectroscopy and scanning electron microscopy. These materials have in their crystalline structures centers of pentacoordinated titanium. The samples were produced through two different synthetic routes, both based on Pechini method. Different heat treatments were applied in order to obtain crystalline and disordered materials. The polymeric resins obtained were submitted to Raman spectroscopy, to verify their influence on the different routes used in the powders preparation. These materials were analyzed by X ray diffraction and Raman spectroscopy, to study the thermal evolution of the phases, as well as the structural disorder of the samples. Rietveld refinement were performed on the diffraction patterns of the crystalline samples. The morphology of the samples was investigated by scanning electron microscopy. After structural characterization, luminescent properties of the synthesized powders were studied. These studies were realized using excitation wavelengths of 250 and 488nm. The obtained results showed that Li2TiSiO5 did not present luminescent properties when the excitement wavelength was 250nm but they did when disordered and excited by the 488nm line. On the other hand Na2TiSiO5 samples presented luminescence with excitement of 250nm although didn t present this property when excited with 488nm. For a better understanding of the luminescent properties in the Li2TiSiO5 and Na2TiSiO5 compounds, their electronic structures were investigated by quantum-mechanical studies. This investigation allowed us obtain information about the effects of deformations in the crystalline structure and in the physical properties of these compounds. The obtained results suggest that the luminescent properties can occur by different mechanisms and thus depend on the crystalline structure and the excitement wavelength.
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spelling Albarici, Viviane CristinaLeite, Edson Robertohttp://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4783657E4http://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4701765E0fa6efcf7-390f-49a0-859a-afecd0f659312016-06-02T20:36:31Z2005-01-042016-06-02T20:36:31Z2004-07-30ALBARICI, Viviane Cristina. Synthesis and characterization of powers of Li2TiSiO5 and Na2TiSiO5.. 2004. 98 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2004.https://repositorio.ufscar.br/handle/ufscar/6494This work presents a systematic study of the synthesis and characterization of Li2TiSiO5 and Na2TiSiO5 compounds. We studied their structural, morphologic and luminescent properties using X ray diffraction, Raman spectroscopy and scanning electron microscopy. These materials have in their crystalline structures centers of pentacoordinated titanium. The samples were produced through two different synthetic routes, both based on Pechini method. Different heat treatments were applied in order to obtain crystalline and disordered materials. The polymeric resins obtained were submitted to Raman spectroscopy, to verify their influence on the different routes used in the powders preparation. These materials were analyzed by X ray diffraction and Raman spectroscopy, to study the thermal evolution of the phases, as well as the structural disorder of the samples. Rietveld refinement were performed on the diffraction patterns of the crystalline samples. The morphology of the samples was investigated by scanning electron microscopy. After structural characterization, luminescent properties of the synthesized powders were studied. These studies were realized using excitation wavelengths of 250 and 488nm. The obtained results showed that Li2TiSiO5 did not present luminescent properties when the excitement wavelength was 250nm but they did when disordered and excited by the 488nm line. On the other hand Na2TiSiO5 samples presented luminescence with excitement of 250nm although didn t present this property when excited with 488nm. For a better understanding of the luminescent properties in the Li2TiSiO5 and Na2TiSiO5 compounds, their electronic structures were investigated by quantum-mechanical studies. This investigation allowed us obtain information about the effects of deformations in the crystalline structure and in the physical properties of these compounds. The obtained results suggest that the luminescent properties can occur by different mechanisms and thus depend on the crystalline structure and the excitement wavelength.Este trabalho apresenta um estudo sistemático sobre a síntese e caracterização de Li2TiOSiO4 e de Na2TiOSiO4. Foram estudadas as propriedades estruturais, morfológicas e luminescentes dos pós por intermédio de difração de raios X, espectroscopia Raman e microscopia eletrônica de varredura. Estes materiais possuem em suas estruturas cristalinas centros de titânio pentacoordenados. As amostras foram produzidas por intermédio de duas rotas sintéticas distintas baseadas em métodos tipo Pechini. Foram realizados diferentes tratamentos térmicos obtendo-se materiais cristalinos e desordenados. As resinas poliméricas obtidas foram submetidas à espectroscopia Raman visando-se verificar a influencia das diferentes rotas utilizadas, na síntese dos pós. Estes materiais foram analisados por difração de raios X, espectroscopia Raman, possibilitando assim o estudo da evolução das fases bem como a desordem estrutural das amostras. Foram realizados refinamentos pelo método de Rietveld nos difratogramas das amostras cristalinas. A morfologia das amostras foi examinada por microscopia eletrônica de varredura. Após as caracterizações estruturais, foram estudadas as propriedades luminescentes das amostras. Estes estudos foram realizados utilizando-se dois comprimentos de onda de excitação distintos de sendo estes de 250nm e 488nm. Os resultados obtidos mostraram que as amostras de Li2TiSiO5 não apresentaram propriedades luminescentes quando utilizado comprimento de onda de excitação de 250nm e apresentaram luminescência com excitação de 488nm quando desordenados. Já as amostras de Na2TiSiO5 apresentam luminescência com excitação de 250nm mas não apresentaram esta propriedade quando excitados com 488nm. Para a melhor compreensão a respeito das propriedades luminescentes do Li2TiSiO5 e do Na2TiSiO5 suas estruturas eletrônicas foram investigadas pôr estudos mecânico-quânticos. Esta investigação possibilitou a obtenção de informações a respeito dos efeitos das deformações nas estruturas cristalinas e nas propriedades físicas destes compostos. Os resultados obtidos sugerem que a propriedade luminescente pode ocorrer por diferentes mecanismos e estes são dependentes da estrutura cristalina e do comprimento de onda de excitação.Universidade Federal de Sao Carlosapplication/pdfporUniversidade Federal de São CarlosPrograma de Pós-Graduação em Química - PPGQUFSCarBRSemicondutoresMétodo de PechiniLuminescênciaPó de cerâmica - sínteseCIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICASíntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.Synthesis and characterization of powers of Li2TiSiO5 and Na2TiSiO5.info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesis-1-19c25e6a7-a2cd-4058-97ed-441bc2793123info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALDissVCA.pdfapplication/pdf3105784https://repositorio.ufscar.br/bitstream/ufscar/6494/1/DissVCA.pdfe91490a3a2bbc0c4ef7e860758942adfMD51THUMBNAILDissVCA.pdf.jpgDissVCA.pdf.jpgIM Thumbnailimage/jpeg9281https://repositorio.ufscar.br/bitstream/ufscar/6494/2/DissVCA.pdf.jpg6aa9e13cdf5d23959a81aa94b1ee156dMD52ufscar/64942023-09-18 18:31:11.704oai:repositorio.ufscar.br:ufscar/6494Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:31:11Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false
dc.title.por.fl_str_mv Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
dc.title.alternative.eng.fl_str_mv Synthesis and characterization of powers of Li2TiSiO5 and Na2TiSiO5.
title Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
spellingShingle Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
Albarici, Viviane Cristina
Semicondutores
Método de Pechini
Luminescência
Pó de cerâmica - síntese
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA
title_short Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
title_full Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
title_fullStr Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
title_full_unstemmed Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
title_sort Síntese e caracterização de pós de Li2TiSiO5 e Na2TiSiO5.
author Albarici, Viviane Cristina
author_facet Albarici, Viviane Cristina
author_role author
dc.contributor.authorlattes.por.fl_str_mv http://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4701765E0
dc.contributor.author.fl_str_mv Albarici, Viviane Cristina
dc.contributor.advisor1.fl_str_mv Leite, Edson Roberto
dc.contributor.advisor1Lattes.fl_str_mv http://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4783657E4
dc.contributor.authorID.fl_str_mv fa6efcf7-390f-49a0-859a-afecd0f65931
contributor_str_mv Leite, Edson Roberto
dc.subject.por.fl_str_mv Semicondutores
Método de Pechini
Luminescência
Pó de cerâmica - síntese
topic Semicondutores
Método de Pechini
Luminescência
Pó de cerâmica - síntese
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA
dc.subject.cnpq.fl_str_mv CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA
description This work presents a systematic study of the synthesis and characterization of Li2TiSiO5 and Na2TiSiO5 compounds. We studied their structural, morphologic and luminescent properties using X ray diffraction, Raman spectroscopy and scanning electron microscopy. These materials have in their crystalline structures centers of pentacoordinated titanium. The samples were produced through two different synthetic routes, both based on Pechini method. Different heat treatments were applied in order to obtain crystalline and disordered materials. The polymeric resins obtained were submitted to Raman spectroscopy, to verify their influence on the different routes used in the powders preparation. These materials were analyzed by X ray diffraction and Raman spectroscopy, to study the thermal evolution of the phases, as well as the structural disorder of the samples. Rietveld refinement were performed on the diffraction patterns of the crystalline samples. The morphology of the samples was investigated by scanning electron microscopy. After structural characterization, luminescent properties of the synthesized powders were studied. These studies were realized using excitation wavelengths of 250 and 488nm. The obtained results showed that Li2TiSiO5 did not present luminescent properties when the excitement wavelength was 250nm but they did when disordered and excited by the 488nm line. On the other hand Na2TiSiO5 samples presented luminescence with excitement of 250nm although didn t present this property when excited with 488nm. For a better understanding of the luminescent properties in the Li2TiSiO5 and Na2TiSiO5 compounds, their electronic structures were investigated by quantum-mechanical studies. This investigation allowed us obtain information about the effects of deformations in the crystalline structure and in the physical properties of these compounds. The obtained results suggest that the luminescent properties can occur by different mechanisms and thus depend on the crystalline structure and the excitement wavelength.
publishDate 2004
dc.date.issued.fl_str_mv 2004-07-30
dc.date.available.fl_str_mv 2005-01-04
2016-06-02T20:36:31Z
dc.date.accessioned.fl_str_mv 2016-06-02T20:36:31Z
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dc.identifier.citation.fl_str_mv ALBARICI, Viviane Cristina. Synthesis and characterization of powers of Li2TiSiO5 and Na2TiSiO5.. 2004. 98 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2004.
dc.identifier.uri.fl_str_mv https://repositorio.ufscar.br/handle/ufscar/6494
identifier_str_mv ALBARICI, Viviane Cristina. Synthesis and characterization of powers of Li2TiSiO5 and Na2TiSiO5.. 2004. 98 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2004.
url https://repositorio.ufscar.br/handle/ufscar/6494
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