Phase stability of lithium azide at pressures up to 60 GPa
Phase stability of lithium azide at pressures up to 60 GPa
复制标题
DOI：
10.1088/0953-8984/21/19/195404
复制
发表时间：
2009-05-13
影响因子：
2.7
通讯作者：
Evers, J.
中科院分区：
文献类型：
--
作者：
Medvedev, S. A.;Trojan, I. A.;Evers, J.
我们在室温下静水压至 60 GPa 以上的压力下，通过 X 射线衍射和拉曼光谱研究了叠氮化锂 (LiN(3))。 X 射线衍射分析的结果揭示了环境压力下 C2/m 晶体结构在最高压力下的稳定性。平动模式的压力依赖性为低压（低于 3 GPa）下的有序-无序转变提供了证据，类似于之前在低温下观察到的转变。观察到的结构稳定性表明这种转变与结构变化无关。 LiN3 的相稳定性与叠氮化钠（在环境压力下为同构）相反，叠氮化钠在低于 50 GPa 的压力下已报告了一组相变。
We studied lithium azide (LiN(3)) by x-ray diffraction and Raman spectroscopy at hydrostatic compression up to pressures above 60 GPa at room temperature. The results of x-ray diffraction analyses reveal the stability of the ambient-pressure C2/m crystal structure up to the highest pressure. The pressure dependence of librational modes provides evidence for an order-disorder transition at low pressures (below 3 GPa), similar to the transition observed previously at low temperatures. The observed structure stability indicates that this transition is not associated with structural changes. The phase stability of LiN3 is in contrast to that of sodium azide (which is isostructural at ambient pressure), for which a set of phase transitions has been reported at pressures below 50 GPa.