Infrared spectroscopic study of the dressed rotations of CN- isotopes in alkali halide crystals.
Infrared spectroscopic study of the dressed rotations of CN- isotopes in alkali halide crystals.
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碱金属卤化物晶体中CN-同位素修饰旋转的红外光谱研究。
DOI：
10.1103/physrevb.43.43
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Sievers
中科院分区：
文献类型：
--
作者：
Mungan;Spitzer;Sethna;Sievers
用高分辨红外吸收光谱研究了氰离子掺杂到KCl中的两个同位素N和C在1.7~300K温度范围内的旋转振动光谱，在低掺杂浓度(0.01mol%)下，在光谱中发现了新的结构。当应变被引入晶体中时，观察到这种结构合并成一个单峰，证实了这些线与孤立的氰离子的隧道作用有关。德文郡的势能只能部分解释这种结构。在100K以上，实验数据中的同位素变化是根据单个全局参数来量化的，即在每个温度下两个同位素的整个旋转振动流形的宽度的积分比率。这个参数的值比氰化偶极子在晶体主体中自由旋转的直接模型预测的要小得多，但与修饰转子模型是一致的。
High-resolution infrared absorption spectroscopy has been used to study the roto-vibrational spectra of cyanide ions doped into KCl for the two isotopes $^{12}\mathrm{C}$ $^{14}\mathrm{N}^{\mathrm{\ensuremath{-}}}$ and $^{13}\mathrm{C}$ $^{15}\mathrm{N}^{\mathrm{\ensuremath{-}}}$ in the temperature range 1.7\char21{}300 K. At the lowest temperature studied, new structure has been resolved in the spectra for low dopant concentrations (0.01 mol %). This structure is observed to merge into a single peak when strains are introduced into the crystal, confirming the association of these lines with tunneling by isolated cyanide ions. The structure is only partially explained by the Devonshire potential. Above 100 K, the isotopic variation in the experimental data is quantified in terms of a single global parameter, an integrated ratio of the widths of the entire roto-vibrational manifolds for the two isotopes, at each temperature. The values of this parameter turn out to be much smaller than what is predicted by a straightforward model of a cyanide dipole freely rotating in a crystalline host, but are consistent with a dressed-rotor model.