Many Body Effects in Random Alloys

随机合金中的许多身体效应

• 批准号: 9024955
• 负责人: Michael Thorpe
• 金额: $ 22.1万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-15 至 1994-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9024955&HistoricalAwards=false
• 关键词: Many; Body; Effects; Random; Alloys

Advances in the fabrication of alloys have led to an increased emphasis on accurate structural characterization. The research conducted here involves a study of the internal strains in random solid solutions caused by the size effect of the different atoms. Recent work has shown that analytic solutions are possible in terms of simple lattice integrals which characterize the topological rigidity of the lattice. The many body aspects of dense random arrays of overlapping strain fields are emphasized. The aim of the research is to produce analytical results for physical quantities that can be experimentally measured. These include the Bragg and Huang components of x-ray and neutron diffraction, and the mean and variance of the near neighbor distances obtained from EXAFS experiments. The analytic work will be verified by computer simulations using realistic potentials to generate relaxed samples from which quantities of experimental interest can be extracted. This unified approach will be applied to semiconductors, FCC metals and rare gas solids.

合金制造的进步使人们更加重视精确的结构表征。本文研究的是由不同原子的尺寸效应引起的随机固溶体的内部应变。最近的工作表明，解析解是可能的简单晶格积分，表征晶格的拓扑刚性。强调了重叠应变场密集随机阵列的许多体面。这项研究的目的是产生可以通过实验测量的物理量的分析结果。这些包括x射线和中子衍射的Bragg和Huang分量，以及从EXAFS实验中获得的近邻距离的平均值和方差。分析工作将通过计算机模拟来验证，使用真实的电位来生成松弛样本，从中可以提取出大量的实验兴趣。这种统一的方法将应用于半导体、FCC金属和稀有气体固体。