Collaborative Research: Ab Initio Computation of Phonon Thermal Transport in Crystalline and Disordered Materials

合作研究：晶体和无序材料中声子热传输的从头算

• 批准号: 1066406
• 负责人: Derek Stewart
• 金额: $ 19.94万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1066406&HistoricalAwards=false
• 关键词: Collaborative; Research; Ab; Initio; Computation; Collaborative; Research; Ab; Initio; Computation

1066406StewartThe lattice thermal conductivity is a fundamental thermal transport parameter that determines the utility of materials for specific thermal management applications. Accurate theoretical modeling of the lattice thermal conductivity is essential to numerous fields including microelectronics cooling, thermoelectrics, and even planetary science. The goal of this collaborative research effort between Boston College and Cornell University will be to implement a theoretical approach to calculate the lattice thermal conductivity of crystalline and alloyed materials from first principles. A central feature of this approach is that it has no adjustable parameters.The Cornell site will focus on calculating ab initio harmonic and, where required, anharmonic interatomic force constants (IFCs) for the materials and structures to be investigated. These calculations will be based on density functional perturbation theory. The IFCs are required inputs for phonon dispersions, phonon density of states, and phonon thermal transport calculations from which the lattice thermal conductivity is obtained. The materials to be studied in this project include lead chalcogenides, I-V-VI2 semiconductors, and nanoparticle-in-alloy-structures.The first principles approach has already demonstrated excellent agreement with measured high thermal conductivities of group IV semiconductors. The materials to be studied in this project are unified by their exceptionally low thermal conductivities and therefore provide an excellent test of the robustness of the theory. The measured thermal properties of many of these materials are well characterized and will provide an important check of our calculated adjustable parameter-free results. Good agreement with measured data would further validate the predictive capability of this state-of-the-art theory in studying and understanding thermal transport and the lattice thermal conductivity in a wide range of materials for many thermal management applications.Intellectual merit: Current theories of the lattice thermal conductivity of materials are typically based on either highly parameterized relaxation time approximations or on purely classical molecular dynamics calculations. The rigorous first principles theory proposed here has no adjustable parameters and incorporates fully the quantum mechanical phonon scattering processes. It therefore could provide currently unavailable predictive power to support ongoing and future experimental studies of thermal transport in materials, as well as contributing to the development of new highly efficient materials engineered for desired thermal management applications.Broader impacts: The project will provide training for one postdoctoral researcher at Cornell University and one doctoral graduate student at Boston College. In addition, several undergraduates including those from underrepresented groups will participate through NSF REU programs at both the Boston College and Cornell sites. The computational tools to be developed during this project will be incorporated into the publicly available computing library of the Cornell Nanoscale Science and Technology Facility (CNF). The activity will also benefit society by aiding in the development of new materials with desired thermal transport properties. This will facilitate technological breakthroughs that may lead to the next generation of thermoelectric materials, thermal barrier coating materials, and thermal interface materials.

1066406StewartThe晶格导热率是一个基本的热传输参数，它决定了特定热管理应用的材料的实用性。晶格热导率的准确理论建模对于包括微电子冷却，热电学甚至行星科学在内的许多领域至关重要。 波士顿学院和康奈尔大学之间的合作研究工作的目的是实施一种理论方法，以计算第一原理的结晶和合金材料的晶格导热率。这种方法的一个主要特征是它没有可调节的参数。康奈尔站点将重点侧重于从头开始谐波，并在需要的情况下，用于研究要研究的材料和结构。 这些计算将基于密度功能扰动理论。 需要从中获得晶格导热率的声子分散体，状态的声子密度和调音子热传输计算的输入。 该项目中要研究的材料包括铅硫元元素，I-V-VI2半导体和合金结构中的纳米颗粒。第一个原理方法已经证明了与IV组半导体的高导电率相当的一致性。该项目中要研究的材料由它们异常低的热导率统一，因此为该理论的稳健性提供了出色的测试。 许多这些材料的测量热性能都得到了很好的特征，并将为我们计算出的可调节无参数结果提供重要检查。与测量数据的良好一致性将进一步验证这种最先进的理论在研究和理解热传输方面的预测能力以及在广泛的材料中的晶格导热率，用于许多热管理应用。启动性优点：材料晶格热导热性的当前理论通常是基于高度参数的较高参数式弛豫时间近似或纯种分类的分类或纯种分类的动态。此处提出的严格的第一原理理论没有可调节的参数，并且完全合并了量子机械声子散射过程。因此，它可以为目前无法获得的预测能力提供支持材料中热运输的持续和未来实验研究，并为开发新型高效的高效材料的开发做出了贡献。该项目的影响：该项目将为康奈尔大学的一名博士后研究员和波斯顿学院的一名博士研究生提供培训。 此外，包括代表性不足的团体在内的几名大学生将通过波士顿学院和康奈尔大学的NSF REU计划参加。 该项目期间要开发的计算工具将纳入康奈尔纳米级科学技术设施（CNF）的公开计算库中。 该活动还将通过帮助开发具有所需热运输特性的新材料来使社会受益。这将促进技术突破，这可能导致下一代热电材料，热屏障涂料材料和热界面材料。