1. Repositório Institucional da UFMG
  2. Publicações Científicas e Culturais
  3. Artigo de Periódico
Use este identificador para citar o ir al link de este elemento: http://hdl.handle.net/1843/47196
Registro completo de metadatos
Campo DCValorIdioma
dc.creatorDaniel Sean Cookpt_BR
dc.creatorReza J. Kashtibanpt_BR
dc.creatorKlaus Wilhelm Heinrich Krambrockpt_BR
dc.creatorGeraldo Magela de Limapt_BR
dc.creatorHumberto Osório Stumpfpt_BR
dc.creatorLuciano Roni Silva Larapt_BR
dc.creatorJosé Domingos Ardissonpt_BR
dc.creatorRichard I. Waltonpt_BR
dc.date.accessioned2022-11-11T18:52:07Z-
dc.date.available2022-11-11T18:52:07Z-
dc.date.issued2019-03-12-
dc.citation.volume12pt_BR
dc.citation.issue5pt_BR
dc.citation.spage1pt_BR
dc.citation.epage16pt_BR
dc.identifier.doihttps://doi.org/10.3390/ma12050838pt_BR
dc.identifier.issn19961944pt_BR
dc.identifier.urihttp://hdl.handle.net/1843/47196-
dc.description.resumoThe synthesis of mixed-metal spinels based on substituted γ-Ga₂O₃ is reported using metal acetylacetonate precursors in solvothermal reactions with alcohols as solvents at 240 °C. New oxides of Cr, Mn and Fe have been produced, all of which are formed as nanocrystalline powders, as seen by high-resolution transmission electron microscopy (HR-TEM). The first chromium-gallium mixed oxide is thus formed, with composition 0.33Ga1.87Cr0.8O₄ ( = vacant site). X-ray absorption near-edge spectroscopy (XANES) at the chromium K-edge shows the presence of solely octahedral Cr3+, which in turn implies a mixture of tetrahedral and octahedral Ga3+, and the material is stable on annealing to at least 850 °C. An analogous manganese material with average chemical composition close to MnGa₂O₄ is shown to contain octahedral Mn2+, along with some Mn3+, but a different inversion factor to materials reported by conventional solid-state synthesis in the literature, which are known to have a significant proportion of tetrahedral Mn2+. In the case of iron, higher amounts of the transition metal can be included to give an Fe:Ga ratio of 1:1. Elemental mapping using energy dispersive X-ray spectroscopy on the TEM, however, reveals inhomogeneity in the distribution of the two metals. This is consistent with variable temperature 57Fe Mössbauer spectroscopy that shows the presence of Fe2+ and Fe3+ in more than one phase in the sample. Variable temperature magnetisation and electron paramagnetic resonance (EPR) indicate the presence of superparamagnetism at room temperature in the iron-gallium oxides.pt_BR
dc.format.mimetypepdfpt_BR
dc.format.mimetypepdfpt_BR
dc.languageengpt_BR
dc.publisherUniversidade Federal de Minas Geraispt_BR
dc.publisher.countryBrasilpt_BR
dc.publisher.departmentICX - DEPARTAMENTO DE FÍSICApt_BR
dc.publisher.departmentICX - DEPARTAMENTO DE QUÍMICApt_BR
dc.publisher.initialsUFMGpt_BR
dc.relation.ispartofMaterialspt_BR
dc.rightsAcesso Abertopt_BR
dc.subjectFerritept_BR
dc.subjectCrystallisationpt_BR
dc.subjectMagnetismpt_BR
dc.subjectXANESpt_BR
dc.subjectMössbauer spectroscopypt_BR
dc.subjectEPRpt_BR
dc.subject.otherFerritapt_BR
dc.subject.otherCristalizaçãopt_BR
dc.subject.otherMagnetismopt_BR
dc.titleNanocrystalline transition-metal gallium oxide spinels from acetylacetonate precursors via solvothermal synthesispt_BR
dc.typeArtigo de Periódicopt_BR
dc.url.externahttps://www.mdpi.com/1996-1944/12/5/838pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0002-3871-1647pt_BR
dc.identifier.orcidhttps://orcid.org/0000-0002-7562-0285pt_BR
Aparece en las colecciones:Artigo de Periódico

archivos asociados a este elemento:
archivo Descripción TamañoFormato 
Nanocrystalline Transition-Metal Gallium Oxide.pdf5.39 MBAdobe PDFVisualizar/Abrir
Mostrar registro simple del elemento Visualizar estadísticas


Los elementos en el repositorio están protegidos por copyright, con todos los derechos reservados, salvo cuando es indicado lo contrario.