TITLE:
Synthesis, Structural and Photophysical Properties of Gd2O3:Eu3+ Nanostructures Prepared by a Microwave Sintering Process
AUTHORS:
Ana P. de Moura, Larissa H. Oliveira, Icamira C. Nogueira, Paula F. S. Pereira, Maximo S. Li, Elson Longo, José A. Varela, Ieda L. V. Rosa
KEYWORDS:
Gadolinuim Oxide, Europium Luminescence, Nanorods
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.4 No.3,
July
25,
2014
ABSTRACT: In this paper, we report the obtention of gadolinium oxide doped with
europium (Gd2O3:Eu+3) by thermal decomposition
of the Gd(OH)3:Eu3+ precursor prepared by the microwave
assisted hydrothermal method. These systems were analyzed by
thermalgravimetric analyses (TGA/DTA), X-ray diffraction (XRD), structural
Rietveld refinement method, fourrier transmission infrared absorbance
spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM) and
photoluminescence (PL) measurement. XRD patterns, Rietveld refinement analysis
and FT-IR confirmed that the Gd(OH)3:Eu3+ precursor
crystallize in a hexagonal structure and space group P6/m, while the Gd2O3:Eu3+ powders annealed in range of 500°C and 700°C crystallized in a cubic
structure with space group Ia-3. FE-SEM images showed that Gd(OH)3:Eu3+ precursor and Gd2O3:Eu3+ are composed by
aggregated and polydispersed particles structured as nanorods-like morphology.
The excitation spectra consisted of an intense broad band with a maximum at 263
nm and the Eu3+ ions can be
excitated via matrix. The emission spectra presented the characteristics transitions of the Eu3+ ion, whose main emission, , is observed at 612 nm. The photophysical properties indicated that
the microwave sintering treatment favored the Eu3+ ions connected
to the O-Gd linkages in the Gd2O3 matrix. Also, the
emission in the Gd2O3:Eu3+ comes from the
energy transfered from the Gd-O linkages to the clusters in the crystalline
structure.