Probing luminescence of rare earth ions in natural pink fluorites using Raman microscopes
Probing luminescence of rare earth ions in natural pink fluorites using Raman microscopes
复制标题
使用拉曼显微镜探测天然粉红色萤石中稀土离子的发光
DOI：
10.1002/jrs.6383
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发表时间：
2022
影响因子：
2.5
通讯作者：
E. Gnos
中科院分区：
文献类型：
--
作者：
H. Hagemann;S. Ayoubipour;T. Delgado;C. Schnyder;E. Gnos
众所周知，许多天然萤石晶体都含有稀土离子。在这项工作中，研究了一系列粉红色萤石，以证明使用拉曼显微镜可以获得三价稀土离子的高分辨率发射光谱。这些发射光谱原则上允许区分与当二价Ca离子被三价稀土离子取代时所需的电荷补偿相关的局部环境的差异。来自阿尔卑斯山的粉红色萤石在热液条件下生长，导致氧气融入萤石中。在来自 Juchlistock（瑞士伯尔尼）的一份样品中，清楚地识别出了三角形的 Eu3+-氧中心。有趣的是，来自中国（中国内蒙古皇岗矿）的粉红色萤石显示出与阿尔卑斯山截然不同的发射光谱。在该样品中，与CaF2拉曼峰的强度相比，发射带的相对强度要低得多，表明Er3+和Ho3+的含量要低得多，发射波长约为520-560nm。文献实例表明，不同颜色萤石晶体的拉曼测量也可以呈现清晰的稀土光谱。通过扩展，因此可以使用拉曼显微光谱来观察和识别其他矿物晶体中稀土离子的发射光谱，并避免相应观察到的拉曼光谱的错误分配。
It is well‐known that many natural fluorite crystals contain rare earth ions. In this work, a series of pink fluorites is studied to demonstrate that the use of Raman microscopes allows to obtain high resolution emission spectra of trivalent rare earth ions. These emission spectra allow in principle to distinguish differences of the local environment related to the charge compensation necessary when the divalent Ca ion is replaced by a trivalent rare earth ion. The pink fluorites from the Alps have grown under hydrothermal conditions, which results in the incorporation of oxygen into the fluorite. In one sample from Juchlistock (Bern, Switzerland), a trigonal Eu3+‐oxygen center is clearly identified. Interestingly, a pink fluorite from China (Huanggang Mine, Inner Mongolia, China) shows a quite different emission spectrum from those of the Alps. In this sample, the emission bands have much lower relative intensity compared with the intensity of the CaF2Raman peak, indicating a much lower content of Er3+and Ho3+which emit around 520–560 nm. Literature examples show that Raman measurements of differently colored fluorite crystals can also present sharp rare earth spectra. By extension, it is thus possible to observe and identify emission spectra of rare earth ions in other mineral crystals using Raman microspectroscopy and avoid misassignments of the corresponding observed Raman spectra.