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 ...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.展开更多
基金the financial support of the Brazilian research financing institutions:CNPq(INCTMN),CAPES and FAPESP(CEPID).
文摘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.
