Molecular Dynamics and Laboratory Experiments on Diffusion in Liquid Oxides

液态氧化物扩散的分子动力学和实验室实验

• 批准号: 9316390
• 负责人: Frank Richter
• 金额: $ 10.5万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-10-01 至 1997-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316390&HistoricalAwards=false
• 关键词: Molecular; Dynamics; Laboratory; Experiments; Diffusion

9316390 Richter A detailed study of diffusion in molten SiO2 and GeO2 is proposed. Combined Molecular Dynamics (MD) simulations and laboratory experiments for the magnitude, activation energy, and activation volume for the self-diffusion of Si, O, and Ge will be carried out. The laboratory experiments will provide important benchmarks with which to test the validity of MD simulations carried out using a variety of representations of the pair-potentials. Presently used potentials are reasonably successful at reproducing various static properties of liquid SiO2, but they have not been tested in terms of their ability to reproduce kinetic quantities such as the diffusivity of atomic species. Validating the MD simulations for a simple oxides is a necessary first step towards the realistic representation of silicate melts, and will provide a basis for understanding diffusion at an atomistic level. A question of particular interest is why do all recent MD simulations of liquid SiO2 find that the self-diffusion of Si and O are virtually the same while laboratory experiments on mixed oxide systems always find them to be significantly different?

提出了在熔融SiO2和GeO2中扩散的详细研究。结合分子动力学（MD）模拟和实验室实验对Si， O和Ge的自扩散的大小，活化能和活化体积进行了研究。实验室实验将提供重要的基准，用于测试使用各种对势表示进行的MD模拟的有效性。目前使用的电势在再现液态SiO2的各种静态特性方面相当成功，但它们在再现动力学量（如原子种类的扩散率）方面的能力尚未得到测试。验证简单氧化物的MD模拟是实现硅酸盐熔体真实表征的必要的第一步，并将为在原子水平上理解扩散提供基础。一个特别有趣的问题是，为什么最近所有液体SiO2的MD模拟都发现Si和O的自扩散几乎相同，而混合氧化物系统的实验室实验却总是发现它们明显不同？