Electronic structure, growth mechanism and photoluminescence of CaWO4 crystals

dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorCavalcante, L. S.
dc.creatorLongo, V. M.
dc.creatorSczancoski, J. C.
dc.creatorAlmeida, M. A. P.
dc.creatorBatista, A. A.
dc.creatorVarela, José Arana
dc.creatorOrlandi, Marcelo Ornaghi
dc.creatorLongo, Elson
dc.creatorLi, M. Siu
dc.date2014-05-20T14:18:41Z
dc.date2016-10-25T17:40:41Z
dc.date2014-05-20T14:18:41Z
dc.date2016-10-25T17:40:41Z
dc.date2012-01-01
dc.date.accessioned2017-04-05T22:29:09Z
dc.date.available2017-04-05T22:29:09Z
dc.identifierCrystengcomm. Cambridge: Royal Soc Chemistry, v. 14, n. 3, p. 853-868, 2012.
dc.identifier1466-8033
dc.identifierhttp://hdl.handle.net/11449/25637
dc.identifierhttp://acervodigital.unesp.br/handle/11449/25637
dc.identifier10.1039/c1ce05977g
dc.identifierWOS:000298991000021
dc.identifierhttp://dx.doi.org/10.1039/c1ce05977g
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/870504
dc.descriptionIn this paper, aggregated CaWO4 micro-and nanocrystals were synthesized by the co-precipitation method and processed under microwave-assisted hydrothermal/solvothermal conditions (160 degrees C for 30 min). According to the X-ray patterns, all crystals exhibited only the scheelite-type tetragonal structure. The data obtained by the Rietveld refinements revealed that the oxygen atoms occupy different positions in the [WO4] clusters, suggesting the presence of lattice distortions. The crystal shapes as well as its crystallographic orientations were identified by field-emission scanning electron microscopy and high-resolution transmission electron microcopy. Electronic structures of these crystals were evaluated by the first-principles quantum mechanical calculations based on the density functional theory in the B3LYP level. A good correlation was found between the experimental and theoretical Raman and infrared-active modes. A crystal growth mechanism was proposed to explain the morphological evolution. The ultraviolet-visible absorption spectra indicated the existence of intermediary energy levels within the band gap. The highest blue photoluminescence emission, lifetime and quantum yield were observed for the nanocrystals processed in the microwave-assisted solvothermal method.
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.languageeng
dc.publisherRoyal Soc Chemistry
dc.relationCrystEngComm
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.titleElectronic structure, growth mechanism and photoluminescence of CaWO4 crystals
dc.typeOtro


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