Thermal Transport Mechanisms of Metallic Compounds and Low-dimensional Metals by First-principles based Calculations
Date: 2024/01/16 - 2024/01/16
Dissertation Title: Thermal Transport Mechanisms of Metallic Compounds and Low-dimensional Metals by First-principles based Calculations
Speaker: Ao Wang, Ph.D. candidate at UM-SJTU Joint Institute
Time: January 16 from 9:30 a.m., 2024 (Beijing Time)
Location: Room 415B, Longbin Building
Abstract
Thermal transport properties of metals are of great importance for the thermal management in various industrial applications. Despite great effort having been devoted to study the thermal transport mechanism, the understanding of thermal transport for metals, however, evolves relatively slowly. Recently, there has been growing interest in the electronic and phonon thermal transport in metals. The studies mainly focus on elemental metals. In comparison, this dissertation is aiming at developing deeper understandings of thermal transport properties of non-elemental metallic systems, including complex intermetallics, defective metals, and two-dimensional metals. In this dissertation, the relationship between the metallic crystal and its thermal transport properties is elaborated. In metals with a large primitive cell, electrons are the main heat carrier, and the phonon thermal conductivity is severely suppressed. The impact of a vacancy on electron thermal conductivity is related to the density of states contributed from the vacancy atom. Its effect on phonon thermal conductivity is highly related to the mass of the vacancy atom. The impact of functional groups on thermal conductivity is complex, because it is related to electron transport, phonon transport, and their interaction. Some specific functional groups can reduce electron-phonon coupling strength, providing the possibility for increasing the thermal conductivity. This dissertation extends the understanding of thermal transport in metals beyond those elemental metals, and the conclusions are important for the future predictive design of the thermal conductivity of metals.