Proton dynamics and phase transitions in doped ice lattices

掺杂冰晶格中的质子动力学和相变

• 批准号: 245834675
• 负责人: Professor Dr. Roland Böhmer
• 金额: --
• 依托单位: Lehrstuhl für Experimentelle Physik III
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/245834675?language=en
• 关键词: Proton; dynamics; phase; transitions; doped

Apart from hexagonal ice, so abundant on earth, 15 further crystalline polymorphs of ice are known and several more are predicted. Ice XIII, ice XIV, and ice XV were produced only in the last seven years by doping previously known ice phases. It is well established that defects such as HCl and KOH can accelerate the proton dynamics on ice lattices by orders of magnitude thereby, e.g., facilitating otherwise kinetically inhibited phase transitions. The impact of doping on the motional processes within various ice phases is, however, far from being understood and is to be studied by combining dielectric spectroscopy with magnetic resonance techniques and accompanying computer simulations. For cubic ice, clathrat-like ice lattices, as well as for metastable high-pressure ice phases that can be stabilized at ambient pressure below temperatures of about 150 K, it is the goal of this project to unravel the dynamics of ice-specific point defects, to understand the transformation kinetics of various phases also within large electrical fields, and to clarify the microscopic nature of the motional mechanisms accompanying the phase transitions of ice.

除了地球上如此丰富的六边形冰之外，已知还有15种冰的结晶多晶型，并且预测还有几种。冰XIII，冰XIV和冰XV是在过去的七年中通过掺杂以前已知的冰相而生产的。众所周知，诸如HCl和KOH的缺陷可以将冰晶格上的质子动力学加速几个数量级，从而，促进否则动力学抑制的相变。然而，掺杂对各种冰相内运动过程的影响远未被理解，并将通过将介电谱与磁共振技术和伴随的计算机模拟相结合来研究。对于立方冰、网格状冰晶格以及可以在低于约150 K的温度的环境压力下稳定的亚稳高压冰相，该项目的目标是解开冰特定点缺陷的动力学，了解各种相在大电场内的转变动力学，并阐明冰相变运动机制的微观本质。