纳米晶Y_2O_3:Eu~(3+)的反常拉曼散射(英文)

作者用燃烧法制备了8nm-50nm的系列纳米晶Y2O3:Eu3+,利用XRD谱确定了纳米晶的晶体结构及晶粒大小。利用两套由不同波长的激光所激发的拉曼光谱,指认了纳米晶Y2O3:Eu3+的拉曼振动模,研究其拉曼光谱。与传统的拉曼光谱学相比较,光谱呈现出明显的反常,其一,是斯托克斯与相对应的反斯托克斯谱峰波数不相等;其二,随晶粒的减小,拉曼谱有明显的变化,包括谱峰的微移、半高宽的增加,以及谱峰强度比的强烈变化;其三,随着激发波长的变化,光谱也呈现出峰位移动的明显变化。这些反常的散射光谱的变化源于纳米结构的本征缺陷。

Abnormal Raman Scattering of Nanocrystalline of Y2O3:Eu3+

The nanocrystalline Y2O3:Eu3 was synthesized by the gel combustion method.The crystal structure were studied using powder X-ray diffraction analysis(XRD),The vibration modes of the nanocrystalline Y2O3:Eu3 at room temperature were identified using two Raman spectrometers.Nanocrystalline(NCs) of Y2O3:Eu3 ,In contrast to traditional Raman scattering theory,the absolute value of the Raman frequency of the anti-Stokes peak is not the same as that of the corresponding Stokes peak,and the Raman scatter showed obvious nanoeffect with the decrease of the NCs size,including the shifts of the peaks,the widening of the FWHM and special change of the intensity ratio between the peaks.Another distinct abnormal phenomena is the Raman scattering changed with the excitated pump laser.It was demonstrated that the abnormal originates from the nanoscale structure of the NCs that can be considered naturally as an intrinsic defect.