Thermal and structural modification in transparent and magnetic germanoborate glasses induced by Gd2O3

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dc.contributor.authorFernandes, Roger Gomes [UNESP]
dc.contributor.authorFranco, Douglas Faza [UNESP]
dc.contributor.authorMastelaro, Valmor Roberto
dc.contributor.authorCardinal, Thierry
dc.contributor.authorToulemonde, Olivier
dc.contributor.authorNalin, Marcelo [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.contributor.institutionUniversidade de São Paulo (USP)
dc.contributor.institutionUniversité de Bordeaux
dc.date.accessioned2020-12-12T01:30:46Z
dc.date.available2020-12-12T01:30:46Z
dc.date.issued2020-10-01
dc.description.abstractA series of new transparent and magnetic germanoborate glasses in the system (100-x)[60GeO2–25B2O3–10Na2O–4Al2O3–1PbO] – (x) Gd2O3, with x = 0, 1, 2, 5, 10, 15 and 20 mol%, was prepared and studied with respect to their thermal and structural changes in the presence of Gd2O3. Based on Differential Scanning Calorimetre (DSC) analysis, a glass with 5% of Gd2O3 showed a high thermal stability, which progressively decreases for samples with higher content of Gd2O3. By the analysis of Raman and Fourier Transform Infrared (FTIR) spectra, it was possible to identify that by increasing the amount of Gd2O3, a progressive depolymerization of 6-membered Ge[IV] rings is promoted, concomitant with an increase of Ge[IV] tetrahedra units with non-briding oxygens. The structural analysis through the local-sensitive techniques EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-ray Absorption Near Edge Structure) showed that the short-range structural modification around the elements Ge and Gd3+ does not change with the addition of Gd2O3 and the presence of germanium four-fold coordination [GeIV] and Gd3+ states, respectively. A simulation of the coordination number (N), the interatomic distance (R) of Ge–O and Gd–O bonds and the Debye-Waller factor was also carried out. The microstructure, after crystallization, of the sample with 15 mol% of Gd2O3 was evaluated using optical and electron microscopes. Finally, the paramagnetic behaviour and ion probe quantification of Gd3+ ions were obtained based on magnetic susceptibility measurements.en
dc.description.affiliationSão Paulo State University (Unesp) Institute of Chemistry
dc.description.affiliationSão Carlos Institute of Physics University of São Paulo (USP)
dc.description.affiliationICMCB CNRS Université de Bordeaux
dc.description.affiliationUnespSão Paulo State University (Unesp) Institute of Chemistry
dc.description.sponsorshipCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.description.sponsorshipASCRS Research Foundation
dc.description.sponsorshipFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.description.sponsorshipIdFAPESP: 2013/07793-6
dc.description.sponsorshipIdFAPESP: 2019/01223-0
dc.format.extent22079-22089
dc.identifierhttp://dx.doi.org/10.1016/j.ceramint.2020.05.227
dc.identifier.citationCeramics International, v. 46, n. 14, p. 22079-22089, 2020.
dc.identifier.doi10.1016/j.ceramint.2020.05.227
dc.identifier.issn0272-8842
dc.identifier.scopus2-s2.0-85087825130
dc.identifier.urihttp://hdl.handle.net/11449/199099
dc.language.isoeng
dc.relation.ispartofCeramics International
dc.sourceScopus
dc.subjectGermanoborate glasses
dc.subjectMagnetic susceptibility
dc.subjectMagneto-optical materials
dc.subjectVibrational spectroscopy
dc.subjectX-ray absorption spectroscopy
dc.titleThermal and structural modification in transparent and magnetic germanoborate glasses induced by Gd2O3en
dc.typeArtigo

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