Evaluación de las propiedades luminiscentes y detección de Eu2+ en partículas nanoestructuradas del sistema Gd2-xEuxO3 (x= 0.05, 0.10 y 0.30)

2012 
espanolMediante el metodo de Spray Pirolisis (SP) operando a 700oC y en atmosfera de aire seco, se obtuvieron particulas nanoestructuradas de composicion Gd2-xEuxO3 (x= 0.05, 0.10 y 0.30) partiendo de las respectivas disoluciones acuosas de nitratos (0.1M). En el presente trabajo, se estudiaron tres muestras con distinta concentracion de europio correspondiente al 1, 2 y 6% atomico. Posteriormente, las particulas nanoestructuradas obtenidas se sometieron a distintos tratamientos termicos comprendidos entre 800 y 1000oC/12h en atmosfera de aire. Las particulas obtenidas se caracterizaron mediante tecnicas de DRX, SEM, dispersion laser y medidas de fluorescencia en estado estacionario. Se ha podido identificar la existencia de dos fases cristalinas cubicas con distinta simetria (Ia-3 y Fm-3m) en las muestras “as-prepared”. Ademas, se ha demostrado la presencia de una fase de Gd2O3 monoclinica (C2/m), la cual desaparece con los tratamientos termicos posteriores. En todas las muestras tratadas termicamente se observa la estabilizacion de la fase cubica mas estable con simetria Ia-3. Mediante medidas de emision de fluorescencia se ha podido detectar en todas las muestras estudiadas la presencia de Eu2+ (l=430nm), independientemente del porcentaje de Eu3+. EnglishSpray Pyrolysis (SP) is performed at 700oC in dry air atmosphere using common nitrate aqueous solutions (0,1M) as precursor in order to obtain nanostructured particles with the composition Gd2-xEuxO3 (x= 0.05, 0.10 and 0.30). In this work, three samples with different atomic europium concentration (1, 2 and 6%) were studied. After, the obtained particles were subjected to different thermal treatments with varying temperatures between 800 and 1000oC/12 h in dry air atmosphere. The obtained particles were characterized by XRD, SEM techniques, laser dispersion and steady state fluorescence spectroscopy. The existence of two cubic phases with different symmetry cubic phases (Ia-3, Fm-3m) was identified within the “as-prepared” samples. Moreover, the presence of Gd2O3 monoclinic phase (C2/m) which disappears during the thermal treatments was proved. In all thermally treated samples, it was observed the stabilization of an only Ia-3 phase. Fluorescence emission measurements in all studied samples the presence of Eu2+ (l= 430nm), whose intensity increases as long as the content of the monoclinic phase decreases of the Eu3+ percentage.
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