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本文利用高温原位拉曼光谱技术,测定了非线性光学晶体硼酸铯锂(CsLiB6O10,CLBO)晶体及其熔体的变温拉曼光谱。利用密度泛函理论计算了基本单元为(B3O7)5-六元环的CLBO晶体的拉曼光谱,并对振动模式进行了分析归属。在升温过程中,CLBO晶体的拉曼光谱出现展宽和红移,无相变发生;在熔化过程中,CLBO晶体微结构中(B3O7)5-六元环的[BO4]四面体发生异构化反应,转变为[BO3]三角形,即晶体相中的(B3O7)5-环变为熔体中的(B3O6)3-环。利用量子化学从头计算方法计算分析了熔体中结构基元的拉曼光谱谱学特征,结合熔体实测结果,表明CLBO熔体的阴离子基元为四个(B3O6)3-六元环组成的大四元环超级结构。
In this paper, high temperature in situ Raman spectroscopy was used to determine the temperature-dependent Raman spectra of CsLiB6O10 and CLBO crystals. The Raman spectra of CLBO crystals with basic unit (B3O7) 5- six-membered rings were calculated by using density functional theory, and the vibration modes were analyzed. Raman spectra of CLBO crystals show broadening and redshift without phase transition during the heating process. During the melting process, the [BO4] tetrahedra of (B3O7) 5- (B3O7) 5-ring in the crystalline phase to a (B3O6) 3-ring in the melt. The Raman spectra of the structural elements in the melt were calculated and calculated by ab initio calculations. The results showed that the anionic motif of the CLBO melt consisted of four (B3O6) 3-membered rings Big four ring super structure.