Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico
Autor(a) principal: | |
---|---|
Data de Publicação: | 2015 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/7337 |
Resumo: | In this work, calcium molybdate (CaMoO4) crystals, MgTiO3 (MTO) thin films and beta zinc molybdate (b-ZnMoO4) microcrystals were synthesized by the different methods and structurally characterized X-ray diffraction (XRD), Rietveld refinement, Fourier transform Raman (FT-Raman) and Fourier transform infrared (FT-IR) spectroscopies. A combined theoretical and experimental study on the electronic structure and photoluminescence (PL) properties these materials has been employed. Their optical properties were investigated by ultraviolet-visible (UV-vis) absorption spectroscopy and PL measurements. First-principles quantum mechanical calculations based on the density functional theory at the B3LYP calculation level have been carried out. The blue and green PL emissions observed in these crystals of the CaMoO4 were ascribed to the intermediary energy levels arising from the distortions on the [MoO4] clusters due to intrinsic defects in the lattice of anisotropic/isotropic crystals. Band structure and Density of states descried the levels energy and a direct gap (G-G). In principle, the theoretical data suggested a strong hybridization between the O 2p (above the VB) and Mo 4d orbitals (near the CB), respectively. Band structure results indicate an indirect band gap for ordered and disordered models of the MgTiO3 in different regions of the Brilouin zone and density of states (DOS) show creates new levels energy with the dislocated Ti atom. The charge maps were used in this structure to verify densities charge distributed asymmetrically, contributing to the formation densities of electrons and holes in the structure. With relation the b-ZnMoO4, the theoretically calculated results of IR and Raman frequencies are in agreement with experimental results. UV-vis absorption measurements shows an optical band gap value of 3.17 eV, while the calculated band structure has a value of 3.22 eV. The density of states indicate that the main orbitals involved in the electronic structure of b-ZnMoO4 crystals are oxygen 2p in the valence band and Mo 4d in the conduction band. |
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Moraes, Eduardo deSilva, Elson Longo dahttp://lattes.cnpq.br/9848311210578810Moraes, Valeria Longo448caf41-9f38-4246-8c4f-128dbac600b62016-09-21T18:17:54Z2016-09-21T18:17:54Z2015-03-06MORAES, Eduardo de. Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico. 2015. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2015. Disponível em: https://repositorio.ufscar.br/handle/ufscar/7337.https://repositorio.ufscar.br/handle/ufscar/7337In this work, calcium molybdate (CaMoO4) crystals, MgTiO3 (MTO) thin films and beta zinc molybdate (b-ZnMoO4) microcrystals were synthesized by the different methods and structurally characterized X-ray diffraction (XRD), Rietveld refinement, Fourier transform Raman (FT-Raman) and Fourier transform infrared (FT-IR) spectroscopies. A combined theoretical and experimental study on the electronic structure and photoluminescence (PL) properties these materials has been employed. Their optical properties were investigated by ultraviolet-visible (UV-vis) absorption spectroscopy and PL measurements. First-principles quantum mechanical calculations based on the density functional theory at the B3LYP calculation level have been carried out. The blue and green PL emissions observed in these crystals of the CaMoO4 were ascribed to the intermediary energy levels arising from the distortions on the [MoO4] clusters due to intrinsic defects in the lattice of anisotropic/isotropic crystals. Band structure and Density of states descried the levels energy and a direct gap (G-G). In principle, the theoretical data suggested a strong hybridization between the O 2p (above the VB) and Mo 4d orbitals (near the CB), respectively. Band structure results indicate an indirect band gap for ordered and disordered models of the MgTiO3 in different regions of the Brilouin zone and density of states (DOS) show creates new levels energy with the dislocated Ti atom. The charge maps were used in this structure to verify densities charge distributed asymmetrically, contributing to the formation densities of electrons and holes in the structure. With relation the b-ZnMoO4, the theoretically calculated results of IR and Raman frequencies are in agreement with experimental results. UV-vis absorption measurements shows an optical band gap value of 3.17 eV, while the calculated band structure has a value of 3.22 eV. The density of states indicate that the main orbitals involved in the electronic structure of b-ZnMoO4 crystals are oxygen 2p in the valence band and Mo 4d in the conduction band.Neste trabalho, cristais de molibdato de cálcio (CaMoO4), filmes finos de MgTiO3 (MTO) e microcristais de beta molibdato de zinco (b-ZnMoO4) foram sintetizados por diferentes métodos e estruturalmente caracterizados por Difração de Raios-X (DRX), refinamento Rietveld, espectroscopia por transformada de Fourier Raman (FT-Raman) e espectroscopia por transformada de Fourier de infravermelho (FT-IR). Empregou-se o estudo teórico e experimental combinados na compreensão das propriedades de estrutura eletrônica e da fotoluminescência (FL) desses materiais. Suas propriedades ópticas foram investigadas por (UV-vis) espectroscopia de absorção ultravioleta-visível e medidas de PL. Foram realizados cálculos de primeiros princípios da mecânica quântica com base na teoria do funcional da densidade (DFT) com o funcional B3LYP. As emissões FL nas regiões do azul e verde observadas nos cristais de CaMoO4 foram atribuídas aos níveis de energia intermediários decorrentes das distorções no cluster de [MoO4] devido a defeitos intrínsecos na estrutura de anisotrópicos/cristais isotrópicos. Estrutura de banda e densidade de estados descreveram os níveis energia e um gap direto (GG). Em princípio, os dados teóricos sugeriram uma forte hibridização entre os orbitais 2p dos átomos O (acima da banda de valência) e dos orbitais 4d dos átomos de Mo (perto da banda de condução), respectivamente. Resultados da estrutura de bandas indicam um gap indireto para os modelos ordenados e desordenado para o MgTiO3 em diferentes regiões da zona Brilouin e a densidade de estados (DOS) mostram novos níveis de energia com o atomo de Ti deslocado. Os mapas de carga foram utilizados nesta estrutura para verificar densidades de cargas distribuidas de forma assim´etrica, contribuindo para a formação de densidades de el´etrons e buracos na estrutura. Com relação ao b-ZnMoO4, os resultados calculados teoricamente das freqüências Raman e IR estão de acordo com os resultados experimentais. Medições de absorção UV-vis mostram um valor gap de 3,17 eV, enquanto a estrutura de banda calculada tem um valor de 3,22 eV. A densidade de estados indica que os principais orbitais envolvidos na estrutura eletrônica dos cristais de b-ZnMoO4 são orbitais 2p do oxigênio na banda de valência e orbitais 4d do Mo na banda de condução.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)porUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Química - PPGQUFSCarFotoluminescênciaAb-initioDFTCRYSTAL - Quantum chemistry ab initio programCIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICAFotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teóricoPhotoluminecence of the CaMoO4, MgTiO3 and b-ZnMoO4: an theoretical studyinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisOnline600600858e0964-d787-4b05-8cfd-92ebfc20599einfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALTeseEM.pdfTeseEM.pdfapplication/pdf53347773https://repositorio.ufscar.br/bitstream/ufscar/7337/1/TeseEM.pdff53113264e0bcc4d094801930562f0f5MD51LICENSElicense.txtlicense.txttext/plain; charset=utf-81957https://repositorio.ufscar.br/bitstream/ufscar/7337/2/license.txtae0398b6f8b235e40ad82cba6c50031dMD52TEXTTeseEM.pdf.txtTeseEM.pdf.txtExtracted texttext/plain208601https://repositorio.ufscar.br/bitstream/ufscar/7337/3/TeseEM.pdf.txt73b34ffaccbd989a92e33b4ff05e906cMD53THUMBNAILTeseEM.pdf.jpgTeseEM.pdf.jpgIM Thumbnailimage/jpeg9256https://repositorio.ufscar.br/bitstream/ufscar/7337/4/TeseEM.pdf.jpg79864d9bbdd3613438ab2a11222ca14fMD54ufscar/73372023-09-18 18:31:10.688oai:repositorio.ufscar.br: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Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:31:10Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico |
dc.title.alternative.eng.fl_str_mv |
Photoluminecence of the CaMoO4, MgTiO3 and b-ZnMoO4: an theoretical study |
title |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico |
spellingShingle |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico Moraes, Eduardo de Fotoluminescência Ab-initio DFT CRYSTAL - Quantum chemistry ab initio program CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA |
title_short |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico |
title_full |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico |
title_fullStr |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico |
title_full_unstemmed |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico |
title_sort |
Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico |
author |
Moraes, Eduardo de |
author_facet |
Moraes, Eduardo de |
author_role |
author |
dc.contributor.author.fl_str_mv |
Moraes, Eduardo de |
dc.contributor.advisor1.fl_str_mv |
Silva, Elson Longo da |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/9848311210578810 |
dc.contributor.advisor-co1.fl_str_mv |
Moraes, Valeria Longo |
dc.contributor.authorID.fl_str_mv |
448caf41-9f38-4246-8c4f-128dbac600b6 |
contributor_str_mv |
Silva, Elson Longo da Moraes, Valeria Longo |
dc.subject.por.fl_str_mv |
Fotoluminescência Ab-initio DFT |
topic |
Fotoluminescência Ab-initio DFT CRYSTAL - Quantum chemistry ab initio program CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA |
dc.subject.eng.fl_str_mv |
CRYSTAL - Quantum chemistry ab initio program |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA |
description |
In this work, calcium molybdate (CaMoO4) crystals, MgTiO3 (MTO) thin films and beta zinc molybdate (b-ZnMoO4) microcrystals were synthesized by the different methods and structurally characterized X-ray diffraction (XRD), Rietveld refinement, Fourier transform Raman (FT-Raman) and Fourier transform infrared (FT-IR) spectroscopies. A combined theoretical and experimental study on the electronic structure and photoluminescence (PL) properties these materials has been employed. Their optical properties were investigated by ultraviolet-visible (UV-vis) absorption spectroscopy and PL measurements. First-principles quantum mechanical calculations based on the density functional theory at the B3LYP calculation level have been carried out. The blue and green PL emissions observed in these crystals of the CaMoO4 were ascribed to the intermediary energy levels arising from the distortions on the [MoO4] clusters due to intrinsic defects in the lattice of anisotropic/isotropic crystals. Band structure and Density of states descried the levels energy and a direct gap (G-G). In principle, the theoretical data suggested a strong hybridization between the O 2p (above the VB) and Mo 4d orbitals (near the CB), respectively. Band structure results indicate an indirect band gap for ordered and disordered models of the MgTiO3 in different regions of the Brilouin zone and density of states (DOS) show creates new levels energy with the dislocated Ti atom. The charge maps were used in this structure to verify densities charge distributed asymmetrically, contributing to the formation densities of electrons and holes in the structure. With relation the b-ZnMoO4, the theoretically calculated results of IR and Raman frequencies are in agreement with experimental results. UV-vis absorption measurements shows an optical band gap value of 3.17 eV, while the calculated band structure has a value of 3.22 eV. The density of states indicate that the main orbitals involved in the electronic structure of b-ZnMoO4 crystals are oxygen 2p in the valence band and Mo 4d in the conduction band. |
publishDate |
2015 |
dc.date.issued.fl_str_mv |
2015-03-06 |
dc.date.accessioned.fl_str_mv |
2016-09-21T18:17:54Z |
dc.date.available.fl_str_mv |
2016-09-21T18:17:54Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
MORAES, Eduardo de. Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico. 2015. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2015. Disponível em: https://repositorio.ufscar.br/handle/ufscar/7337. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/7337 |
identifier_str_mv |
MORAES, Eduardo de. Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico. 2015. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2015. Disponível em: https://repositorio.ufscar.br/handle/ufscar/7337. |
url |
https://repositorio.ufscar.br/handle/ufscar/7337 |
dc.language.iso.fl_str_mv |
por |
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por |
dc.relation.confidence.fl_str_mv |
600 600 |
dc.relation.authority.fl_str_mv |
858e0964-d787-4b05-8cfd-92ebfc20599e |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Química - PPGQ |
dc.publisher.initials.fl_str_mv |
UFSCar |
publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.source.none.fl_str_mv |
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