Orientational Glasses and High Pressure Phases Studied by NMR

定向玻璃中的冻结性质是迄今为止的一个问题。 开放的问题。 拟议的实验工作将调查 冻结是否是随机的 温度跃变核 磁共振将被用来确定是否 单个分子在重复时返回到相同的取向， 融化和冻结。 实验将使用经过充分研究的 定向玻璃，氰溴化钾和钠， 氰化钾 这些实验应该会带来更多 对物质玻璃态的详细了解。 对高压下简单分子固体的研究 发现了新的固相。 然而，迄今为止， 研究了这些固体的动力学。 特别是 尚不清楚高压下的取向无序 无序相是静态的或动态的。 核磁 金刚石压砧单元中的共振，一种最近开发的技术， 将用于研究定向动力学。 扩散将 也可以测量，以寻找机制的变化， 密度 这项工作将从氮气和一氧化碳开始开始 因为有可靠的相图， 分子相似性 这项工作应扩大 了解高密度材料。

The nature of freezing in orientational glasses is as yet an open question. The proposed experimental work will investigate whether the freezing is random. Temperature-jump nuclear magnetic resonance will be employed to determine whether individual molecules return to the same orientation upon repeated melting and freezing. The experiments will use the well-studied orientational glasses potassium cyanide-bromide and sodium- potassium cyanide. The experiments should lead to a more detailed understanding of the glassy state of matter. Studies of simple molecular solids at high pressures have found new solid phases. However, almost none of the work to date has studied the dynamics of these solids. In particular, it is not known whether the orientational disorder in the high pressure disordered phases is static or dynamic. Nuclear magnetic resonance in diamond anvil cells, a recently developed technique, will be used to study the orientational dynamics. Diffusion will also be measured to look for a change in mechanism at high densities. The work will begin with nitrogen and carbon monoxide because reliable phase diagrams are available and because of their molecular similarities. The work should extend the understanding of high density materials.