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《无机发光材料物理与化学》课程学术讲座之9-10讲
更新日期:2018-11-23  
《无机发光材料物理与化学》课程学术讲座第9-10讲:Spectroscopic Studies of Europium-Doped Calcium Fluoride Nanoparticles
主讲人:Mike Reid教授
单位:新西兰Canterbury大学物理和化学学院
时间:2018年11月29日11:00AM
地点:纳米楼一楼报告厅
Abstract:
    Lanthanide-doped luminescent nanoparticles are important candidates for low-toxicity imaging agents and intracellular nano-thermometers for biomedical applications. Lanthanide ions doped into bulk CaF2 crystals are known to form a variety of sites, and to form clusters at concentrations as low as 0.01 mol%, becoming the dominant centre by 0.1 mol%. This clustering gives enhanced energy transfer, promising significant improvements in applications requiring up-conversion or down-conversion via energy transfer. 
Previous work on lanthanide-doped CaF2 nanoparticles has made use of low-resolution spectroscopy at high temperatures, and was therefore unable to clearly discriminate between the different sites. Indeed, work on sodium-stabilized Eu3+-doped CaF2 nanoparticles [4] makes the assumption that the sites are predominately C4v(F-), though sodium is known to suppress C4v(F-) sites in bulk crystals. 
In this work we present high resolution laser spectroscopy of CaF2:Eu3+ nano-particles at cryogenic temperatures (10 K), including site-selective excitation, emission, and lifetime measurements. Samples include core-only and core-shell particles with a variety of concentrations and preparation techniques. C4v(F-) sites appear to be suppressed in these materials. An enhancement of Oh and C2v(Na+), sites, and evidence of cluster and surface sites is observed.
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简介:
Mike Reid教授现任新西兰Canterbury大学物理和化学科学学院的院长,是国际知名的稀土光谱理论专家,他首创的f族元素电子结构与跃迁计算程序包,用户遍及全球,为目前该领域最权威的计算软件。他也是中科院海西研究院固体光谱学和光物理国际研究中心的国际顾问委员。 本次系列讲座他将在主讲2次课程,第一次为稀土离子在晶体材料中的电子和超精细能级结构介绍,第二次为稀土纳米发光材料光谱学。