本文测定了钠氟石(NaF·2CaO·SiO2)的常温拉曼光谱, 并运用Dmol3密度泛函(DFT) 理论对其晶体中主要结构单元的简正振动模式进行了计算。通过实验值与计算值的比较, 确定了其特征峰的归属。同时, 采用高温拉曼光谱仪原位实测了钠氟石在不同的升温速率下的变温拉曼光谱。研究表明, 钠氟石在缓慢升温过程中会分解成NaF和Ca2SiO4; 快升至熔点附近, 熔化成液态, 快冷至室温, 仍分解成β- Ca2SiO4。

In this paper, room temperature Raman spectrum of calcium sodium fluoride silicate (NaF·2CaO·SiO2) was recorded and Dmol3 density functional theory (DFT) simulation method was applied to calculate normal vibration modes of NaF·2CaO·SiO2 crystal. By comparing the experimental and calculated results, vibrational modes can be assigned. High temperature Raman spectroscopy was also used to investigate the temperature dependent in situ Raman spectra of calcium sodium fluoride silicate at different rates of heating processing. The results showed that calcium sodium fluoride silicate would be decomposed NaF and Ca2SiO4 while being slowly heated. The crystal can transform into liquid state above its melting point only by being fast heated, however, it was convinced that NaF·2CaO·SiO2 finally decomposed into β- Ca2SiO4 after by being fast cooled from its molten state to ambient temperature.