Cubic and Hexagonal NaGdF4 Crystals Precipitated from an Aluminosilicate Glass: Preparation and Luminescence Properties
Cubic and Hexagonal NaGdF4 Crystals Precipitated from an Aluminosilicate Glass: Preparation and Luminescence Properties
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DOI：
10.1021/cm401454y
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发表时间：
2013-07-23
影响因子：
8.6
通讯作者：
Ruessel, Christian
中科院分区：
文献类型：
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作者：
Herrmann, Andreas;Tylkowski, Maxi;Ruessel, Christian
根据玻璃的组成和提供的退火程序，在系统SiO2/Al 2 O3/AlF 3/Na 2 O/Gd 2 O3/SmF 3中的硅酸盐玻璃的热退火导致立方或六方NaGdF 4纳米晶体的沉淀。这些玻璃在铸造后已经发生了相分离，形成了一种据说富含氟化物和稀土元素的液滴相。液滴的尺寸主要在80至120 nm的范围内。在温度>= 600 ℃的退火过程中，立方或六方NaGdF 4的多核颗粒在非晶液滴相内部沉淀。在此体系中可以得到完全透明的六方NaGdF 4纳米微晶玻璃。Sm ~（3+）的荧光光谱和荧光衰减曲线显示出晶相效应。Sm ~（3+）掺杂的六方NaGdF_4具有与立方NaGdF_4不同的荧光发射光谱和更长的荧光寿命。
Depending on the composition of the glass and the annealing procedure supplied, thermal annealing of silicate glasses in the system SiO2/Al2O3/AlF3/Na2O/Gd2O3/SmF3 led to the precipitation of cubic or hexagonal NaGdF4 nanocrystals. The glasses were already phase separated after casting and formed a droplet phase supposedly enriched in fluorides and rare earths. The droplets had sizes mainly in the range from 80 to 120 nm. During annealing at temperatures >= 600 degrees C, multicore particles of cubic or hexagonal NaGdF4 were precipitated inside the amorphous droplet phase. Completely transparent hexagonal NaGdF4 containing nano-glass-ceramics could be derived from this system. Fluorescence spectra and fluorescence decay curves of Sm3+ show crystal phase dependent effects. Sm3+ doped hexagonal NaGdF4 exhibits notably different fluorescence emission spectra and longer fluorescence lifetimes than cubic NaGdF4.