摘要
控制不同的烧结条件,制备了Eu3+掺杂La2O3 3B2O3体系的晶体及玻璃材料。在这两种组分相同但物相不同的基质中,Eu3+离子表现出不同的光谱性质。通过对比两种材料的发射光谱、声子边带、电荷迁移带及荧光寿命,讨论了Eu3+离子周围局域结构的改变对其发光性质的影响。
The local structure of rareearth ions in solid host is of great research interest for designing new luminescence materials, and Eu3+ ion is a good probe to reflect the local environment around rareearth ions in different materials. In this paper, Eu3+doped La2O33B2O3 crystal and glass samples were prepared by solidstate reaction under different calcination temperatures. By controlling calcination temperatures at 960℃ and 1 200℃, respectively, the crystal and glass samples with the same composition were obtained. The Eu3+ ions in the two samples present different flourescent properties. With the excitation of 394nm ultraviolet light, the glass sample presents an intense 618nm emission, while the crystal sample gives a dominant 696nm emission. The emission spectra, the phonon sideband spectra, the charge transfer bands and the lifetimes were measured to clarify the different luminescence of the two samples. In the emission spectra, both of the two figures (Fig1, Fig2) present the characteristic luminescence of Eu3+ ion, including emission peaks at 590nm (5D0→7F1), 618nm (5D0→7F2) , 650nm (5D0→7F3), 696nm (5D0→7F4). Among these transitions, the 5D0→7F1 transition is a magnetic dipole transition, and the 5D0→7F2 transition is an electric dipole transition. It was found that, with the transition from crystal phase to glass phase, the intensity ratio of 5D0→7F2 to 5D0→7F2 of Eu3+ ion was enhanced, which indicates that the value of JO parameter Ω2 was increased. The local structures around Eu3+ ion in the two different host were investigated by measuring the charge transfer bands and the phonon sideband spectra associated with the 5D2←7F0 transition. It was concluded that B-O vibrational mode inside the various borate rings and nonbridging B-O-1 bonds stretching mode with phonon energy of 1 900, 1 500cm-1, respectively, exist in both of the two samples. The charge transfer bands confirmed that the near coordination ions of Eu3+ are different in the two samples.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2003年第5期512-516,共5页
Chinese Journal of Luminescence
基金
国家重点基础研究发展规划(973稀土
G1998061309)
国家自然科学基金(10274082)资助项目
