Florencite is a hydrous light rare-earth elements (LREE) aluminium phosphate [REEAl₃(PO₄)₂(OH)₆], that amongst the REE-rich minerals is quite common. The main end-members are Ce-, La- and Nd-rich terms that were found in several genetic environments. Despite the large occurrence worldwide, to the authors' knowledge, florencite has attracted very few studies, particularly concerning the characterization of its Raman spectrum. We present a detailed study of the Raman spectrum of florencite, combining experimental measurements and theoretical calculations. Experimental Raman spectra (in the 100–1300 cm⁻¹ spectral range) are measured on four florencite samples characterized by different chemical composition, that is, different REE abundance. The results highlight a remarkable coincidence between different Raman spectra measured on each sample, despite the significantly different chemical compositions in terms of their REE content. The same similarities were also observed in the computed spectra at the ab initio level; moreover, the calculations allowed the attributions of the different Raman signals to specific vibrational modes.

中文翻译：

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萤石-(REE) [REEAl3(PO4)2(OH)6] 的拉曼光谱：一种综合实验和计算方法

萤石是一种水合轻稀土元素（LREE）磷酸铝[REEAl ₃ (PO ₄ ) ₂ (OH) ₆ ]，在富含稀土元素的矿物中相当常见。主要末端成员是在多种遗传环境中发现的富含 Ce、La 和 Nd 的项。尽管在世界范围内大量出现，但据作者所知，佛罗伦萨石引起的研究很少，特别是关于其拉曼光谱的表征。我们结合实验测量和理论计算，对荧光石的拉曼光谱进行了详细研究。实验拉曼光谱（在 100–1300 cm ^-1光谱范围内）是在四个具有不同化学成分（即不同 REE 丰度）的荧光石样品上测量的。结果突显了每个样品测量的不同拉曼光谱之间的显着一致性，尽管其稀土元素含量的化学成分显着不同。在从头计算的光谱中也观察到了相同的相似性；此外，计算允许将不同的拉曼信号归因于特定的振动模式。