CAREER: Superdiffusive Heat Transfer in Nanoscale Metal Multilayers

职业：纳米级金属多层中的超扩散传热

• 批准号: 1847632
• 负责人: Richard Wilson
• 金额: $ 51.41万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1847632&HistoricalAwards=false
• 关键词: CAREER; Superdiffusive; Heat; Transfer; Nanoscale

Classical theory for macroscopic heat transport poorly predicts the evolution of heat in metals at the nanoscale, especially on ultrafast timescales, e.g. a trillionth of a second. Engineers working in these areas must currently rely on simplistic models and incomplete data to estimate transport in metals following laser excitation. This project seeks to replace such guess work with a concrete framework for modelling transport. The new framework will be extensively tested though experimentation. Using a combination of short optical and electrical pulses to heat nanoscale metal systems, this project will measure heat transfer over the time- and length-scales that cannot be predicted by existing theory. This research will be integrated with outreach to middle and high school students in the predominantly Hispanic local community surrounding UCR. The research will also be integrated with a mentoring program designed to get promising community college students involved in research and encourage them to transfer to UCR to pursue science and engineering degrees.The goal of this CAREER project is to identify, quantify, and ultimately control the electron-electron and electron-phonon scattering processes that govern heat flow in nanoscale metal multilayers. On time-scales shorter than electronic scattering processes, heat transfer can either be ballistic, superdiffusive, or diffusive. To identify the time- and length-scales over which various heat transfer regimes apply, and to quantify the governing electronic scattering processes, this project uses a combination of ultrafast thermometry methods such as wavelength-dependent time-domain thermoreflectance measurements, time-resolved magneto-optic Kerr effect measurements, and temperature dependent electrical conductivity at THz frequencies. These methods measure the evolution of heat in metal multilayers on sub-picosecond time-scales. Experimental data on the spatial and temporal evolution of heat in nanoscale metal layers are used to test first-principles based models for hot electron transport. The results of this project significantly advance the basic science of nanoscale heat transfer, and therefore allow improvements in technologies where thermal management is of critical importance, e.g. nanoelectronics.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.

宏观热传输的经典理论很难预测金属在纳米尺度上的热量演化，特别是在超快时间尺度上，例如。万亿分之一秒。在这些领域工作的工程师目前必须依靠简单的模型和不完整的数据来估计激光激发后金属的传输。该项目旨在用具体的运输建模框架来取代这种猜测工作。新框架将通过实验进行广泛的测试。该项目将利用短光脉冲和电脉冲的组合来加热纳米级金属系统，测量现有理论无法预测的时间和长度尺度上的传热。这项研究将与加州大学河滨分校周边以西班牙裔为主的当地社区的中学生和高中生的外展活动相结合。该研究还将与一项指导计划相结合，该计划旨在让有前途的社区学院学生参与研究，并鼓励他们转学到加州大学河滨分校攻读科学和工程学位。这个职业项目的目标是识别、量化并最终控制控制纳米级金属多层中热流的电子-电子和电子-声子散射过程。在比电子散射过程更短的时间尺度上，传热可以是弹道式、超扩散式或扩散式。为了确定各种传热机制适用的时间和长度尺度，并量化控制电子散射过程，该项目结合使用了超快测温方法，例如波长相关的时域热反射测量、时间分辨磁光克尔效应测量以及太赫兹频率下温度相关的电导率。 这些方法在亚皮秒时间尺度上测量金属多层中的热量演变。纳米级金属层中热量的空间和时间演化的实验数据用于测试基于第一原理的热电子传输模型。该项目的结果显着推进了纳米级传热的基础科学，因此可以改进热管理至关重要的技术，例如热管理技术。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

In situ and ex situ processes for synthesizing metal multilayers with electronically conductive interfaces

• DOI: 10.1063/5.0084573
• 发表时间: 2022-06
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: Frank Angeles;Xinping Shi;Richard B. Wilson

Differentiating contributions of electrons and phonons to the thermoreflectance spectra of gold

• DOI: 10.1103/physrevmaterials.5.106001
• 发表时间: 2021-03
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: Kexin Liu;Xinping Shi;Frank Angeles;R. Mohan;J. Gorchon;Sinisa Coh;Richard B. Wilson

Thermal Conductivity of BAs under Pressure

• DOI: 10.1002/aelm.202200017
• 发表时间: 2021-10
• 期刊: Advanced Electronic Materials
• 影响因子: 6.2
• 作者: Songrui Hou;Bo Sun;F. Tian;Q. Cai;Y. Xu;Shanmin Wang;Wanyue Peng;Xi Chen;Z. Ren

Response of vibrational properties and thermal conductivity of perovskites to pressure

钙钛矿的振动特性和热导率对压力的响应

• DOI: 10.1016/j.mtphys.2023.101010
• 发表时间: 2023
• 期刊: Materials Today Physics
• 影响因子: 11.5
• 作者: Hou, Songrui;Wilson, Richard B.;Li, Chen
• 通讯作者: Li, Chen