Rosa Ieda L V, Marques Ana Paula A, Tanaka Marcos T S, Motta Fabiana V, Varela José A, Leite Edson R, Longo Elson
LIEC-CMDMC, DQ, UFSCar, Via Washington Luiz, km 235, CEP 13565-905, São Carlos, SP, Brazil.
J Fluoresc. 2009 May;19(3):495-500. doi: 10.1007/s10895-008-0438-7. Epub 2008 Nov 11.
BaMoO(4):Eu (BEMO) powders were synthesized by the polymeric precursor method (PPM), heat treated at 800 degrees C for 2 h in a heating rate of 5 degrees C/min and characterized by powder X-ray diffraction patterns (XRD), Fourier Transform Infra-Red (FTIR) and Raman spectroscopy, besides room temperature Photoluminescence (PL) measurements. The emission spectra of BEMO samples under excitation of 394 nm present the characteristic Eu(3+) transitions. The relative intensities of the Eu(3+) emissions increase as the concentration of this ion increases from 0.01 to 0.075 mol, but the luminescence is drastically quenched for the Ba(0.855)Eu(0.145)MoO(4) sample. The one exponential decay curves of the Eu(3+ 5)D(0)-->(7)F(2) transition, lambda (exc) = 394 nm and lambda (em) = 614 nm, provided the decay times of around 0.54 ms for all samples. It was observed a broadening of the Bragg reflections and Raman bands when the Eu(+3) concentration increases as a consequence of a more disordered material. The presence of MoO(3) and Eu(2)Mo(2)O(7) as additional phases in the BEMO samples where observed when the Eu(3+) concentration was 14.5 mol%.
采用聚合物前驱体法（PPM）合成了BaMoO(4):Eu（BEMO）粉末，在800℃下以5℃/min的升温速率热处理2 h，并通过粉末X射线衍射图谱（XRD）、傅里叶变换红外光谱（FTIR）和拉曼光谱进行表征，此外还进行了室温光致发光（PL）测量。BEMO样品在394 nm激发下的发射光谱呈现出Eu(3+)的特征跃迁。随着该离子浓度从0.01 mol增加到0.075 mol，Eu(3+)发射的相对强度增加，但对于Ba(0.855)Eu(0.145)MoO(4)样品，发光急剧猝灭。Eu(3+)的5D(0)-->(7)F(2)跃迁（激发波长λ(exc)=394 nm，发射波长λ(em)=614 nm）的单指数衰减曲线表明，所有样品的衰减时间约为0.54 ms。观察到随着Eu(+3)浓度增加，由于材料更加无序，布拉格反射和拉曼带变宽。当Eu(3+)浓度为14.5 mol%时，在BEMO样品中观察到存在MoO(3)和Eu(2)Mo(2)O(7)作为额外相。
