Dynamical Properties of Frustrated Molecular Solids at Low Temperatures

低温下受阻分子固体的动力学性质

• 批准号: 9623536
• 负责人: Neil Sullivan
• 金额: $ 30万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9623536&HistoricalAwards=false
• 关键词: Dynamical; Properties; Frustrated; Molecular; Solids

9623536 Sullivan This project will investigate the dynamical properties of frustrated quench-disordered systems at low temperatures. These studies will focus on determining the important low-energy collective excitations in prototypical orientation glasses (orthoand para-dihydrogen and dinitrogen-argon solid mixtures), and the behavior of quantum quadrupoles in reduced geometries - two dimensional arrays and surface-melted quantum latticed fluids. The proposed experiments involve several different NMR and thermodynamic measurements to determine the nature of the lowfrequency thermal relaxation and the effect of lattice geometry on the ordering of classical and quantum rotors in orientational glasses. New experiments will also probe quantum exchange in multilayers of dihydrogen and in helium-3 films physisorbed on square-lattice substrates for which the combined effects of frustration and disorder are predicted to lead to nuclear spin glass phases. The project is of fundamental character but the results may provide insights into the properties of glasses which are widely employed in technical and commercial applications. %%% This project will investigate the dynamical properties of frustrated, quench-disordered systems at low temperatures. These studies will focus on determining the important low-energy collective excitations in prototypical orientation glasses (orthoand para-dihydrogen and dinitrogen-argon solid mixtures), and the behavior of quantum quadrupoles in reduced geometries - two dimensional arrays and surface-melted quantum latticed fluids. The proposed experiments involve several different NMR and thermodynamic measurements to determine the nature of the lowfrequency thermal relaxation and the effect of lattice geometry on the ordering of classical and quantum rotors in orientational glasses. New experiments will also probe quantum exchange in multilayers of dihydrogen and in helium-3 films physisorbed on square-lattice substrates for which the combined effects of frustration and disorder are predicted to lead to nuclear spin glass phases. The project is of fundamental character but the results may provide insights into the properties of glasses which are widely employed in technical and commercial applications. ***

9623536沙利文这个项目将研究低温下失控失序系统的动力学性质。这些研究将集中于确定原型取向玻璃(正、副二氢和二氮-氩固体混合物)中重要的低能集体激发，以及简化几何结构中量子四极子的行为--二维阵列和表面熔化的量子晶格流体。这些实验包括几种不同的核磁共振和热力学测量，以确定低频热弛豫的性质，以及晶格几何对取向玻璃中经典和量子转子有序性的影响。新的实验还将探索氢气多层膜和物理吸附在正方形晶格衬底上的氦-3薄膜中的量子交换，预计受挫和无序的综合效应将导致核自旋玻璃相。该项目具有根本性的特点，但其结果可能会为深入了解玻璃的特性提供参考，这种玻璃在技术和商业应用中被广泛使用。这个项目将研究受挫失序系统在低温下的动力学性质。这些研究将集中于确定原型取向玻璃(正、副二氢和二氮-氩固体混合物)中重要的低能集体激发，以及简化几何结构中量子四极子的行为--二维阵列和表面熔化的量子晶格流体。这些实验包括几种不同的核磁共振和热力学测量，以确定低频热弛豫的性质，以及晶格几何对取向玻璃中经典和量子转子有序性的影响。新的实验还将探索氢气多层膜和物理吸附在正方形晶格衬底上的氦-3薄膜中的量子交换，预计受挫和无序的综合效应将导致核自旋玻璃相。该项目具有根本性的特点，但其结果可能会为深入了解玻璃的特性提供参考，这种玻璃在技术和商业应用中被广泛使用。***