Effect of Zn2+ ions on the structure, morphology and optical properties of CaWO4 microcrystals
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
18/03/2015
18/03/2015
01/12/2014
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Resumo |
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Processo FAPESP: 12/18597-0 Processo FAPESP: 09/50303-4 Processo FAPESP: 13/07296-2 The effect of zinc ions (Zn2+) on the structure, morphology and optical properties of (Ca1-x Zn (x) )WO4 microcrystals with (x = 0, 0.01, 0.02, and 0.03) obtained by the microwave-hydrothermal method at 170 A degrees C for 1 h is reported in this letter. These microcrystals were characterized by X-ray diffraction (XRD), Rietveld refinement, energy dispersive X-rays spectroscopy (EDXS) and field emission scanning electron microscopy (FE-SEM) images. The optical properties were investigated by ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy and photoluminescence (PL) measurements. XRD patterns and Rietveld refinement data indicated that all the (Ca1-x Zn (x) )WO4 microcrystals present a tetragonal structure and a reduction of lattice parameters and unit cell volume occurs with the increase of Zn2+. EDXS data confirms that the elemental chemical composition was achieved for (Ca1-x Zn (x) )WO4 microcrystals. FE-SEM images showed that the replacement of Ca2+ by the Zn2+ promotes a reduction of average crystals size and considerable changes in crystal shape starting from dumbbell-like to decorative ball-like (Ca1-x Zn (x) )WO4 microcrystals. UV-Vis spectra evidenced a small increase in optical band gap values (from 5.72 to 5.76 eV). Finally, PL emission of (Ca1-x Zn (x) )WO4 microcrystals was improved until x = 0.02 due to the presence of defects at medium range and new intermediate electronic levels in the band gap associated to the Zn2+ content. |
Formato |
648-654 |
Identificador |
http://dx.doi.org/10.1007/s10971-014-3550-y Journal Of Sol-gel Science And Technology. Dordrecht: Springer, v. 72, n. 3, p. 648-654, 2014. 0928-0707 http://hdl.handle.net/11449/116324 10.1007/s10971-014-3550-y WOS:000345089200026 |
Idioma(s) |
eng |
Publicador |
Springer |
Relação |
Journal Of Sol-gel Science And Technology |
Direitos |
closedAccess |
Palavras-Chave | #CaWO4 #Microcrystals #Zinc #Distortions #Photoluminescence |
Tipo |
info:eu-repo/semantics/article |