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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Luminescence properties of alpha-Ag2WO4 nanorods co-doped with Li+ and Eu3+ cations and their effects on its structure

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Author(s):
Pinatti, Ivo M. [1, 2] ; Fern, George R. [2] ; Longo, Elson [1] ; Ireland, Terry G. [2] ; Pereira, Paula F. S. [1] ; Rosa, V, Ieda L. ; Silver, Jack [2]
Total Authors: 7
Affiliation:
[1] V, Univ Fed Sao Carlos, Chem Dept, LIEC, INCTMN, POB 676, BR-13565905 Sao Carlos, SP - Brazil
[2] Brunel Univ London, Wolfson Ctr Mat Proc, Kingston Lane, Uxbridge UB8 3PH, Middx - England
Total Affiliations: 2
Document type: Journal article
Source: Journal of Luminescence; v. 206, p. 442-454, FEB 2019.
Web of Science Citations: 3
Abstract

Nanorods of the formula alpha-(Ag2-3x-yEuxLiy)WO4 (where x = 0.01 y = 0.01-0.03 mol) were efficiently synthesized via a low temperature (90 degrees C) co-precipitation (CP) method. They were structurally characterised using both: X-ray powder diffraction (Rietveld refinement) and low temperature (20 degrees C to -19 degrees C) micro-Raman spectroscopy. The morphology of the nanorods was confirmed with field emission scanning electron microscopy. The peaks in the XRD patterns of alpha-(Ag2-3x-yEuxLiy)WO(4 )samples were all indexed to the pure orthorhombic phase of alpha-(Ag2-3x-yEuxLiy)WO4 and are in good accordance with ICSD no 4165. These results indicate that Eu3+ and Li+ ions have both been introduced efficiently into the alpha-Ag2WO4 lattice. Moreover, the Li+ co-dopant facilitated smoother incorporation of Eu 3+ concentration into the alpha-Ag2WO4 lattice with less distortion of the lattice. In addition the presence of the Li+ co-dopant eases strain in the lattice and this allows the incorporated Eu3+ cations to emit red light much more efficiently. This is seen for alpha-(Ag2-3x-yEuxLiy)WO4 (where x = 0.01, y = 0.02 mol) in which the optimum red emission is observed. Analysis of the emission spectra in respect to the known metal coordination sites in the structure suggest the Eu3+ cations are only in Ag1 and Ag2 sites which are coordinated by seven O atoms (AgO7 deltahedral polyhedrons). This finding is also confirmed by the photoluminescent decay curves which can be analysed in terms of one depopulation mechanism is in accord with the occurrence of a single coordination environment for the Eu3+ cations. Although the co-doped alpha-(Ag2-3x-yEuxLiy)WO4 phosphors are much brighter than those containing no Li+ cations they are not bright enough (as yet) to be used in commercial devices. (AU)

FAPESP's process: 13/23995-8 - Synthesis of silver tungstate doped with Eu3+ and the study of their optical, photoluminescent and photocatalytic properties
Grantee:Ivo Mateus Pinatti
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 15/13669-1 - Structural and photoluminescence properties of Eu3+ doped Ag2WO4 synthesized by the green coprecipitation methodology
Grantee:Ivo Mateus Pinatti
Support type: Scholarships abroad - Research Internship - Doctorate
FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC