Effect of alkaline modifiers on the structural, optical and crystallization properties of niobium germanate glasses and glass-ceramics

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MetadadosDescriçãoIdioma
Autor(es): dc.contributorUniv Fed Alfenas-
Autor(es): dc.contributorUniversidade Estadual Paulista (Unesp)-
Autor(es): dc.creatorNascimento Guedes, Luis Felipe-
Autor(es): dc.creatorMarcondes, Lia Mara [UNESP]-
Autor(es): dc.creatorEvangelista, Renato Oliveira-
Autor(es): dc.creatorBatista, Gislene-
Autor(es): dc.creatorMendoza, Valentina Gacha-
Autor(es): dc.creatorCassanjes, Fabia Castro-
Autor(es): dc.creatorPoirier, Gael Yves-
Data de aceite: dc.date.accessioned2022-02-22T00:05:49Z-
Data de disponibilização: dc.date.available2022-02-22T00:05:49Z-
Data de envio: dc.date.issued2020-12-09-
Data de envio: dc.date.issued2020-12-09-
Data de envio: dc.date.issued2020-07-01-
Fonte completa do material: dc.identifierhttp://dx.doi.org/10.1016/j.optmat.2020.109866-
Fonte completa do material: dc.identifierhttp://hdl.handle.net/11449/195433-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/11449/195433-
Descrição: dc.descriptionAlkali niobium germanate glasses were prepared by melt-quenching in the ternary systems 75GeO(2)-15Nb(2)O(5)-10M(2)O with M = Li, Na, K, Rb and Cs. Thermal properties of these glasses and related glass-ceramics are strongly dependent on the alkaline modifier. Structural investigations by Raman allowed to determine that the alkali radius has an influence on the number of non-bridging oxygens and consequently on the average glass network connectivity. Raman spectra of sodium, potassium and rubidium germanate glass-ceramics exhibited slight changes when compared to the pristine glass and the new Raman features can be attributed to a 3D NbO6 network similar to orthorhombic niobium oxide. Characterization of the heat-treated glasses allowed to determine the crystalline phases precipitated in the samples and it has been shown that a single perovskite bronze-like phase of general formula M2Nb5O21 can be obtained in Na, K, and Rb-containing glasses. Luminescent properties of Eu3+-doped glasses pointed out a non-regular tendency where sodium-based glass seems to be the inflexion point of luminescent data with higher asymmetry around Eu3+ ions and higher quantum efficiency. In transparent glass-ceramics, the Eu3+ luminescent properties are clearly modified in the Na- and K-based samples with lower symmetry and quantum efficiency after heat-treatment. Such optical behavior is attributed to Eu3+ migration in the perovskite crystalline phase with highly distorted Eu3+ sites and shorter Eu3+-Eu3+ distances.-
Descrição: dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)-
Descrição: dc.descriptionFundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)-
Descrição: dc.descriptionFINEP-
Descrição: dc.descriptionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)-
Descrição: dc.descriptionUniv Fed Alfenas, Grp Quim Mat, Campus Pocos De Caldas, Pocos De Caldas, MG, Brazil-
Descrição: dc.descriptionUniv Estadual Paulista, Inst Quim, Araraquara, SP, Brazil-
Descrição: dc.descriptionUniv Estadual Paulista, Inst Quim, Araraquara, SP, Brazil-
Descrição: dc.descriptionCNPq: 156420/2018-0-
Formato: dc.format8-
Idioma: dc.languageen-
Publicador: dc.publisherElsevier B.V.-
Relação: dc.relationOptical Materials-
???dc.source???: dc.sourceWeb of Science-
Palavras-chave: dc.subjectGlass-
Palavras-chave: dc.subjectGlass-ceramic-
Palavras-chave: dc.subjectGermanate-
Palavras-chave: dc.subjectNiobium-
Palavras-chave: dc.subjectAlkali-
Título: dc.titleEffect of alkaline modifiers on the structural, optical and crystallization properties of niobium germanate glasses and glass-ceramics-
Tipo de arquivo: dc.typelivro digital-
Aparece nas coleções:Repositório Institucional - Unesp

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