Fotoluminescência do CaMoO4, MgTiO3 e b-ZnMoO4: um estudo teórico

Detalhes bibliográficos
Autor(a) principal: Moraes, Eduardo de
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.
id SCAR_0a9151f9fd75a6dd4c4e9862115838b7
oai_identifier_str oai:repositorio.ufscar.br:ufscar/7337
network_acronym_str SCAR
network_name_str Repositório Institucional da UFSCAR
repository_id_str 4322
spelling 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
language 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 reponame:Repositório Institucional da UFSCAR
instname:Universidade Federal de São Carlos (UFSCAR)
instacron:UFSCAR
instname_str Universidade Federal de São Carlos (UFSCAR)
instacron_str UFSCAR
institution UFSCAR
reponame_str Repositório Institucional da UFSCAR
collection Repositório Institucional da UFSCAR
bitstream.url.fl_str_mv https://repositorio.ufscar.br/bitstream/ufscar/7337/1/TeseEM.pdf
https://repositorio.ufscar.br/bitstream/ufscar/7337/2/license.txt
https://repositorio.ufscar.br/bitstream/ufscar/7337/3/TeseEM.pdf.txt
https://repositorio.ufscar.br/bitstream/ufscar/7337/4/TeseEM.pdf.jpg
bitstream.checksum.fl_str_mv f53113264e0bcc4d094801930562f0f5
ae0398b6f8b235e40ad82cba6c50031d
73b34ffaccbd989a92e33b4ff05e906c
79864d9bbdd3613438ab2a11222ca14f
bitstream.checksumAlgorithm.fl_str_mv MD5
MD5
MD5
MD5
repository.name.fl_str_mv Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)
repository.mail.fl_str_mv
_version_ 1802136303517564928