Ciezak Jennifer A, Jenkins Timothy A, Liu Zhenxian, Hemley Russell J
BWCD-PSB-WMRD, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, USA.
J Phys Chem A. 2007 Jan 11;111(1):59-63. doi: 10.1021/jp063150q.
Vibrational spectroscopy has been used to investigate the room-temperature high-pressure phases of the energetic material hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The pressure-induced alterations in the spectral profiles were studied in a compression sequence to 30.2 GPa using Raman spectroscopy and to 26.6 GPa using far-infrared spectroscopy. At pressures near 4.0 GPa, several changes become immediately apparent in the Raman spectrum, such as large frequency shifts, mode splittings, and intensity changes, which are associated with a phase transition from alpha-RDX to gamma-RDX. Our study extends the kinetic stability of gamma-RDX to pressures near 18.0 GPa. Evidence for a new phase was found at pressures between 17.8 and 18.8 GPa and is based on the appearance of new vibrational bands and associated changes in intensity patterns. The new phase has vibrational characteristics that are similar to those of beta-RDX, suggesting the two polymorphs share a related crystal structure.
振动光谱已被用于研究含能材料六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）的室温高压相。使用拉曼光谱在压缩至30.2吉帕的过程中以及使用远红外光谱在压缩至26.6吉帕的过程中研究了光谱轮廓中压力诱导的变化。在接近4.0吉帕的压力下，拉曼光谱中立即出现了几个明显的变化，如大的频率位移、模式分裂和强度变化，这些与从α-RDX到γ-RDX的相变有关。我们的研究将γ-RDX的动力学稳定性扩展到接近18.0吉帕的压力。在17.8至18.8吉帕之间的压力下发现了一个新相的证据，其基于新振动带的出现和强度模式的相关变化。新相具有与β-RDX相似的振动特性，表明这两种多晶型物具有相关的晶体结构。
