Y_2Zr_2O_7:Eu^(3+)纳米微粒的合成与变温发光特性研究

Combustion Synthesis and Temperature Dependent Photoluminescence of Nanocrystalline Y_2Zr_2O_7:Eu^(3+)

采用低温燃烧法制备了Y2Zr2O7∶Eu3+纳米微粒,用XRD和HRTEM对纳米微粒的结构、形貌进行了分析和表征.作为对比,采用高温固相法制备了Y2Zr2O7∶Eu3+体相材料,对其变温发光特性进行了测试和对比研究.结果表明,Y2Zr2O7∶Eu3+纳米晶的606和628nm发射(5D0→7F2)最强,与5D0→7F1磁偶跃迁相对发光强度较体相材料增强60%,且随着温度的降低,Eu3+离子5D0→7FJ(J=1,2,3,4)跃迁发光强度均有变化.另外,采用盐酸"浸蚀"技术对Y2Zr2O7∶Eu3+纳米微粒进行了表面处理,室温发射光谱测试表明:5D0→7F2,3,4电偶跃迁与5D0→7F1磁偶跃迁的相对强度较表面处理前减小约15%.对观测到的结果通过纳米微粒的表面效应和激活离子所处局域环境的变化进行了定性解释和讨论.

Nanocrystal and bulk Y2 Zr2O7 ： Eu^3＋ were prepared by combustion synthesis and solid-state reaction, respectively. By using X-ray diffraction （XRD）, high resolution transmission electron microscope （HRTEM） and fluorescence spectrometer, the structural, morphological and temperature dependent spectro- scopic properties of Y2 Zr2O7 ： Eu^3＋＋ were investigated. The results show that the main emission peaks of Y2 Zr2O7 ： Eu^3＋ nanocrystal are at 606nm and 628nm, which is attributed to ^5D0→^7 F2 transition of Eu^3＋ , the ratio of the intensity of 606nm and 590nm in Y2Zr2O7 ： Eu^3＋ nanocrystal increases 60% than that in bulk Y2 Zr2O7 ： Eu^3＋ , and all the intensities of ^5 D0→^7 FJ （J = 1,2,3,4） transitions change evidently with decreasing temperature. In addition, the fluorescence spectra of the Y2 Zr2O7 ： Eu^3＋ nanoparticles which surface were treated by steeping in hydrochloric acid show that the ratio of the intensity of 606nm and 590nm in surface treated Y2 Zr2O7 ： Eu^3＋ nanoparticles decreases 15% than that in surface untreated Y2 Zr2O7 ： Eu^3＋ nanoparticles. A qualitative explanation and discussion on the above results is presented on base of surface effect and local structural environment of Eu^3＋ ions.