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.

晶体材料的许多物理特性（即电子、光学、热学）源于原子排列的周期性以及波与底层重复结构相互作用的性质。随着纳米技术的出现，现在有机会引入额外的几何结构，包括附加的周期性层，以便在更广泛的空间和时间尺度上操纵属性。 该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的复杂弹性波现象，以及设计具有优越性能和先进功能的集成材料结构系统。这一目标将通过采用构建块方法来实现，其中首先分析和设计单个单元电池。然后，这些电池将在结构层面上使用，以实现目标机械和热性能及功能。为了促进这种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技术。所提出的理论工作将通过实验研究进行验证，将为纳米尺度材料/结构分析和设计提供新方法。这将导致体纳米结构系统以及尺寸减小的纳米机电系统（NEMS）组件的热性能和振动响应特性得到显着改善。特别令人感兴趣的是可实现的材料系统，该系统具有降低的热导率，可实现高效的热电转换，以及能够以最小的散热抑制振动的坚固的纳米级结构。