Anomalous energy transfer in crystalline materials from the viewpoints of discrete mechanics and continuum theory

从离散力学和连续介质理论的角度研究晶体材料中的反常能量传递

• 批准号: 405631704
• 负责人: Professor Dr. Wolfgang H. Müller
• 金额: --
• 依托单位: Fachgebiet Kontinuumsmechanik und Materialtheorie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/405631704?language=en
• 关键词: Anomalous; energy; transfer; crystalline; materials

This project focuses on theoretical and experimental studies of anomalous energy transfer by heat conduction in crystalline lattices. At the nanoscale materials exhibit special thermomechanical properties mostly related to the discreteness of the atomic structure of the medium. An understanding of the energy transfer by heat conduction at that level is essential to obtain a link between the microscopic and the macroscopic descriptions of solids. Latest developments in technology made it possible to investigate properties of low dimensional objects, such as nanotubes, graphene, or fullerenes. During the last decades it was shown that in low dimensional structures, where the phonon mean free path is small compared to the structural size, the nature of heat propagation is ballistic rather than diffusive. Electrical and mechanical properties of low dimensional crystalline structures became of interest during the last decades due to applications in microelectronic devices. Problems of energy transport by heat conduction are of great importance due to problems of cooling and designing innovative thermal devices. Miniaturization of electronic devices and circuits has led to the emergence of self-heating as a critical bottleneck to the performance and reliability of newly developed microelectronic circuits and systems. In order to address heat transfer physics at the single device level, more advanced models of energy transport by heat conduction should be considered. This motivates recent interest in investigating thermal properties of the structures, such as graphene and carbon nanotubes, where such anomalies are most prominent. The aim of this proposal is to investigate anomalous energy transport by heat conduction in low dimensional structures using analytical approaches and simulations, which will help to design and interpret experiments to be performed in order to validate theoretical model predictions.The following will be investigated:- Formulation of discrete and continuous models of anomalous energy transfer in 1D and quasi-1D crystalline materials.- Description of anomalous energy transfer in 2D materials of simple structure.- Development of 2D lattice and continuum models. - Simulation of the energy transfer by heat conduction in such systems using discrete and continuum approaches.- Analogous experiments for the transient case.- Performing experiments determining thermal parameters of nano-structures (graphene) in the non-steady regime using Raman spectroscopy and AFM thermosensors.- Comparison and interpretation of experimental data with results of simulation and analytical studies.Our main objectives:- Create a theory of energy propagation by heat conduction in crystals based on first principles.- Investigate its consistency with extended thermodynamics and phenomenological theories. - Test the models in custom designed experiments

本项目主要研究晶格中通过热传导进行的异常能量转移的理论和实验研究。在纳米尺度下，材料表现出特殊的热机械性能，主要与介质原子结构的离散性有关。在这个层次上理解通过热传导进行的能量传递对于获得固体的微观和宏观描述之间的联系是必不可少的。技术的最新发展使得研究低维物体的性质成为可能，例如纳米管，石墨烯或富勒烯。在过去的几十年中，它表明，在低维结构中，声子平均自由程是小的结构尺寸相比，热传播的性质是弹道，而不是扩散。由于在微电子器件中的应用，低维晶体结构的电学和机械性能在过去几十年中变得令人感兴趣。由于冷却和设计创新热设备的问题，通过热传导的能量传输问题非常重要。电子器件和电路的小型化已经导致自加热作为新开发的微电子电路和系统的性能和可靠性的关键瓶颈的出现。为了解决单个器件级的传热物理问题，应考虑通过热传导进行能量传输的更先进模型。这激发了人们最近对研究石墨烯和碳纳米管等结构的热性质的兴趣，这些结构的异常现象最为突出。本项目的目的是利用分析方法和模拟来研究低维结构中通过热传导进行的异常能量传输，这将有助于设计和解释为了验证理论模型预测而进行的实验。将研究以下内容：-一维和准一维晶体材料中异常能量传输的离散和连续模型的制定。-描述简单结构的二维材料中的异常能量转移。开发二维晶格和连续体模型。- 使用离散和连续方法模拟此类系统中通过热传导进行的能量传递。瞬态情况下的类似实验。使用拉曼光谱和AFM热传感器进行实验，确定纳米结构（石墨烯）在非稳定状态下的热参数。比较和解释实验数据与模拟和分析研究的结果。我们的主要目标：-创建一个理论的能量传播的热传导晶体的基础上的第一原则。-研究它与扩展热力学和唯象理论的一致性。- 在定制设计的实验中测试模型