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角形冰之外，已知还有 15 种冰的多晶型物，并且还预测了更多的冰晶型。 Ice XIII、ice XIV 和ice XV 是在过去七年中通过掺杂先前已知的冰相生产的。众所周知，HCl 和 KOH 等缺陷可以将冰晶格上的质子动力学加速几个数量级，从而促进原本动力学抑制的相变。然而，掺杂对各种冰相内运动过程的影响还远未被理解，需要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、笼形冰晶格，以及可在低于约 150 K 的环境压力下稳定的亚稳态高压冰相，该项目的目标是揭示冰特定点缺陷的动力学，了解大电场内各种相的转变动力学，并阐明伴随相的运动机制的微观性质 冰的转变。