Fan W H, Burnett A, Upadhya P C, Cunningham J, Linfield E H, Davies A G
School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
Appl Spectrosc. 2007 Jun;61(6):638-43. doi: 10.1366/000370207781269701.
Broadband terahertz time-domain spectroscopy (THz-TDS) has been used to measure the far-infrared (FIR) vibrational spectra of several commonly used pure explosives, including 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), 1,3-dinitrato-2,2-bis(nitratomethyl)propane (PETN), and two types of plastic explosive, SEMTEX and SX2. A number of distinct absorption peaks, originating from FIR-active vibrational modes of these polycrystalline energetic materials, were observed in the frequency range 0.3-7.5 THz (10-250 cm(-1)). In addition, the temperature-dependent FIR vibrational spectra of PETN were measured between 4 K and 296 K with several well-resolved absorption peaks observed across this temperature range. We find that as the temperature is reduced, the observed absorption peaks resolve into narrower features and shift towards higher frequencies. The temperature dependence of the spectra is explained in terms of the anharmonicity of the vibrational potentials of crystalline compounds, and an empirical fit is given to describe the peak shift with temperature.
宽带太赫兹时域光谱（THz-TDS）已被用于测量几种常用纯炸药的远红外（FIR）振动光谱，包括2,4,6-三硝基甲苯（TNT）、1,3,5-三硝基全氢-1,3,5-三嗪（RDX）、1,3-二硝基-2,2-双（硝基甲基）丙烷（PETN）以及两种塑性炸药，塞姆汀塑胶炸药和SX2。在0.3-7.5太赫兹（10-250厘米-1）的频率范围内，观察到了源自这些多晶含能材料的FIR活性振动模式的多个明显吸收峰。此外，在4 K至296 K之间测量了PETN随温度变化的FIR振动光谱，在此温度范围内观察到了几个分辨率良好的吸收峰。我们发现，随着温度降低，观察到的吸收峰分解为更窄的特征，并向更高频率移动。根据晶体化合物振动势的非谐性解释了光谱的温度依赖性，并给出了一个经验拟合来描述峰随温度的移动。
