Collective Dynamics and Resonances of Phonons and Dislocations in Thermal Transport

热传输中声子和位错的集体动力学和共振

• 批准号: 2121895
• 负责人: Youping Chen
• 金额: $ 60万
• 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: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2121895&HistoricalAwards=false
• 关键词: Collective; Dynamics; Resonances; Phonons; Dislocations

NONTECHNICAL SUMMARYThis award supports research that will use atomic resolution computer models to determine the nature of interactions between dislocations and atomic vibrations in crystalline materials. Dislocations are ubiquitous defects that involve a sudden irregularity (such as the appearance of an extra row of atoms) in the atomic arrangement of crystalline materials. They often can move through the material when the material is under thermal or mechanical loading. The atoms in a crystal vibrate, with the amplitude of the vibrations increasing with temperature. The movement of dislocations through the crystal can be affected by their interactions with these vibrations in a manner similar to the effect that waves have on the motion of a boat as it moves through the water. This research will quantify such interactions and determine their effect on heat transport through the material. The results of this research will be of fundamental importance to the design of new materials for many applications of heat transport, such as thermoelectrics that can convert heat to electrical energy for a green economy. This award also supports the team’s educational and outreach activities. The PIs will design computational lecture series and mini projects to train undergraduate students every summer during the period of this project. The PIs will also reach out to women and minority students, and students with physical disabilities, to explore their research interests and provide them with research experiences. The datasets and source codes developed under this project will be made freely available to the computational materials science community. The research team will also organize a symposium at an international or national conference on the role of interactions of dislocations with crystal vibrations on heat transport.TEHCNICAL SUMMARYThis award supports research that will elucidate the microscopic processes that describe the interaction between dislocations and phonons and their implications for macroscopic materials phenomena, including plastic flow, internal friction, and thermal resistance. A general description for phonon-dislocation interaction that can provide a quantitative agreement with major experimental results has been a significant challenge, which has limited our understanding of this interaction as well as its effect on thermal transport. This research aims to address this challenge by establishing a multiscale methodology from machine learning of high-fidelity interatomic potentials to concurrent atomistic-continuum simulation of coupled dislocations dynamics and phonon transport. This will enable an accurate description of dislocations in the studies of phonon thermal transport, as well as a visualization of the transient processes of phonon scattering with multiscale details of the physical processes to identify the underlying mechanisms. This award also supports the team’s educational and outreach activities. The PIs will design computational lecture series and mini projects to train undergraduate students every summer during the period of this project. The PIs will also reach out to women and minority students, and students with physical disabilities, to explore their research interests and provide them with research experiences. The datasets and source codes developed under this project will be made freely available to the computational materials science community. The research team will also organize a symposium at an international or national conference on the role of interactions of dislocations with crystal vibrations on heat transport.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术总结该奖项支持将使用原子分辨率计算机模型来确定晶体材料中位错和原子振动之间相互作用的性质的研究。位错是普遍存在的缺陷，涉及晶体材料的原子排列中的突然不规则性（例如出现额外的一排原子）。当材料处于热或机械载荷下时，它们通常可以穿过材料。晶体中的原子振动，振动的幅度随温度而增加。位错在晶体中的运动可以受到它们与这些振动的相互作用的影响，其方式类似于波浪对船在水中运动的影响。这项研究将量化这种相互作用，并确定它们对通过材料的热传输的影响。这项研究的结果将对设计用于许多热传输应用的新材料具有根本重要性，例如可以将热量转换为电能以实现绿色经济的热电材料。该奖项还支持团队的教育和推广活动。本计画期间，研究所将于每年暑假设计计算系列讲座及小型专题，以训练本科生。研究所还将接触妇女和少数民族学生以及身体残疾的学生，探索他们的研究兴趣，并为他们提供研究经验。在该项目下开发的数据集和源代码将免费提供给计算材料科学界。此外，研究小组还将在国际或国内会议上组织关于位错与晶体振动的相互作用对热传输的作用的研讨会。技术概要该奖项支持阐明描述位错与声子之间相互作用的微观过程及其对宏观材料现象（包括塑性流动、内部摩擦和热阻）的影响的研究。 声子位错相互作用的一般描述，可以提供一个定量的协议与主要的实验结果一直是一个重大的挑战，这限制了我们对这种相互作用的理解，以及它对热输运的影响。本研究旨在通过建立一种多尺度方法来应对这一挑战，从高保真原子间势的机器学习到耦合位错动力学和声子输运的并行原子连续模拟。这将使声子热输运的研究中的位错的准确描述，以及与多尺度的物理过程的细节，以确定潜在的机制的声子散射的瞬态过程的可视化。该奖项还支持团队的教育和推广活动。本计画期间，研究所将于每年暑假设计计算系列讲座及小型专题，以训练本科生。研究所还将接触妇女和少数民族学生以及身体残疾的学生，探索他们的研究兴趣，并为他们提供研究经验。在该项目下开发的数据集和源代码将免费提供给计算材料科学界。该研究团队还将在国际或国家会议上组织一次关于位错与晶体振动的相互作用对热传输的作用的研讨会。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估而被认为值得支持。

项目成果

Dislocation formation in the heteroepitaxial growth of PbSe/PbTe systems

PbSe/PbTe 系统异质外延生长中的位错形成

• DOI: 10.1016/j.actamat.2023.119308
• 发表时间: 2023
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: Li, Yang;Gu, Boyang;Diaz, Adrian;Phillpot, Simon R.;McDowell, David L.;Chen, Youping
• 通讯作者: Chen, Youping

Dynamic interaction between phonons and edge dislocations in LiF

LiF 中声子和边缘位错之间的动态相互作用

• DOI: 10.1063/5.0171550
• 发表时间: 2023
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: Li, Yang;Zheng, Zexi;Chen, Xiang;Chen, Youping
• 通讯作者: Chen, Youping