A Building Block Approach to Controlling Phonon Dynamics in Nanostructures

控制纳米结构中声子动力学的积木方法

• 批准号: 0927322
• 负责人: Mahmoud Hussein
• 金额: $ 27万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0927322&HistoricalAwards=false
• 关键词: Building; Block; Approach; Controlling; Phonon

Much of the physical properties (i.e., electronic, optical, thermal) of crystalline materials stems from the periodicity in the atomic arrangement and the nature of wave interactions with the underlying repetitive structure. With the advent of nanotechnology there are now opportunities to introduce additional geometric structures including an added layer of periodicity in order to manipulate properties over broader spatial and temporal scales. The objective of the proposed research is the development of theoretical and computational tools for the analysis and elucidation of complex elastic wave phenomena in periodic nanoscale materials and the design of integrated material-structure systems with superior properties and advanced functionalities. This objective will be approached by adopting a building blocks methodology where single unit cells are first analyzed and designed. The cells will then be utilized at the structural level to achieve target mechanical and thermal properties and functionalities. In order to facilitate this multiscale analysis and design process, techniques for fast lattice dynamics calculations will be developed and utilized.The proposed theoretical work, which will be validated by experimental studies, will enable new approaches for material/structure analysis and design at the nanoscale. This will lead to substantial improvements in thermal properties and vibration response characteristics in bulk nanostructured systems as well as reduced dimension nanoelectromechanical system (NEMS) components. Of particular interest are realizable material systems with reduced thermal conductivity for efficient thermoelectric conversion and robust nanoscale structures capable of suppressing vibration with minimum heat dissipation.

结晶材料的许多物理特性（即电子，光学，热）源于原子布置的周期性以及与基本重复结构的波浪相互作用的性质。随着纳米技术的出现，现在有机会引入其他几何结构，包括附加的周期性层，以在更广泛的空间和时间尺度上操纵属性。 拟议研究的目的是开发理论和计算工具，用于分析和阐明周期性纳米级材料中复杂的弹性波现象以及具有出色特性和高级功能的综合材料结构系统的设计。该目标将通过采用首先分析和设计单个单位单元单元的构件方法来实现。然后，将在结构水平上使用细胞来实现目标机械和热性能和功能。为了促进这一多尺度分析和设计过程，将开发和利用快速晶格动力学计算的技术。拟议的理论工作将通过实验研究验证，将为纳米级的材料/结构分析和设计提供新的方法。这将导致大量纳米结构系统中的热性能和振动响应特性以及降低尺寸纳米电机力学系统（NEMS）组件的显着改善。特别有趣的是可实现的材料系统，具有降低导热率的可有效热电转换和稳健的纳米级结构，能够以最小的散热抑制振动。