Download or read book Phonon Hydrodynamic Transport at Elevated Temperature written by Zhiwei Ding and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For over half a century, phonon hydrodynamic transport was deemed exotic and mattered only at extremely low temperatures. In this work, by combining the theoretical and experimental approach, we successfully predict and confirm the existence of phonon hydrodynamic transport in graphite above 200 K. More specifically, we introduce a direction-dependent definition of normal and Umklapp scattering, which gives an improved description of mode-specific phonon dynamics. By extending the classical Fuchs-Sondheimer solution, we developed a first-principles framework to study phonon hydrodynamics under the size effect with mode-by-mode phonon scattering details. We unambiguously revealed the Poiseuille heat flow by studying the variation of heat flow as the graphite ribbon width and identified for the first time the existence of phonon Knudsen minimum -- an unusual phenomenon unique to hydrodynamic regime -- which can be observed up to 90 K. Using a sub-picosecond transient grating technique, we directly observed second sound in graphite at record-high temperatures of 200 K. With the enlarged grating-period window, we firstly reported the dispersion of thermal wave, whose velocity increases with decreasing grating period. Our experimental findings are well explained with the interplay among "three fluids": ballistic, diffusive, and hydrodynamic phonons. We believe our study may stimulate further work into discovering more material systems possessing significant phonon hydrodynamic features, as well as new research into understanding and manipulating the phonon transport in the hydrodynamic scheme.

Download or read book Characterization of Thermal and Hydrodynamic Phonon Transport Using Transient Thermoreflectance written by Jihoon Jeong and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal management becomes a significant challenge due to generating more power per unit volume in developing high-power density micro-/nano-sized electronics. The critical feature size of nano- or micro-electronics has already reached less than 10 nm. The thermal conductivity of the semiconducting, dielectric, and metallic materials used in fabricating these microelectronics can be reduced significantly at a small dimension because of increased boundary scattering of phonons and electrons, known as the heat carriers in solids. The size effects on the thermal transport property are considered one of the most fundamental problems for thermal management, which needs to be understood thoroughly for next-generation electronic devices' rational design. This work seeks to advance the understanding of how heat travels in solid materials. Utilizing precise methodologies for characterizing thermophysical properties is the most critical job. Transient thermoreflectance (TTR) and grating imaging techniques are developed to measure thermal conductivity in both lateral and horizontal directions. These techniques are employed to study materials from bulk to nanostructure, including thin-film and nanoparticles, to be characterized. A new regime of phonon transport between ballistic and diffusive transports, called hydrodynamic phonon transport, is observed with a novel method of heat pulse measurement. With thermal characterization using the TTR, four bulk materials, including glass, sapphire, GaAs, and Si are examined for interfacial thermal resistance and cross-plane thermal conductivity. Nanostructures are also tested, such as MoS2 thin-films over a wide range of thicknesses and digital alloy samples of GaAs/InAs. Cu nanoparticles' effective thermal properties are also measured, including heat capacity, density, and thermal conductivity to improve laser sintering technology in the additive manufacturing industry. Thermal characterization using the grating imaging technique, the in-plane thermal conductivity is measured in GaAs/AlAs superlattices and Cu nano-films on Si substrate, representing the bulk and layered structures, respectively. A new regime of phonon transport, hydrodynamic, is observed in graphite using optical heat pulse measurement. The measurement results reveal transient lattice cooling near the adiabatic center of a ring-shaped pump beam at temperatures between 80 and 120 K

Download or read book Transport in Phonon Systems written by Vadim Lʹvovich Gurevich and published by North Holland. This book was released on 1986 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Transport in Phonon Systems'' the principles of physical kinetics are given and the description of transport properties in a wide class of macroscopic physical systems - the phonon systems - is presented. Important problems of phonon transport such as thermal conductivity and thermal waves of second sound, dielectric losses, sound propagation and absorption, phonon echo, and phonon transport in superfluid helium II are discussed. Many of these problems are discussed for the first time and the author presents numerous original results. Not only specialists but also those wishing to enter the field of phonon physics and phonon kinetics can benefit from Transport in Phonon Systems''.

Download or read book Nanoscale Energy Transport written by LIAO and published by IOP Publishing Limited. This book was released on 2020-03-20 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together leading names in the field of nanoscale energy transport to provide a comprehensive and insightful review of this developing topic. The text covers new developments in the scientific basis and the practical relevance of nanoscale energy transport, highlighting the emerging effects at the nanoscale that qualitatively differ from those at the macroscopic scale. Throughout the book, microscopic energy carriers are discussed, including photons, electrons and magnons. State-of-the-art computational and experimental nanoscale energy transport methods are reviewed, and a broad range of materials system topics are considered, from interfaces and molecular junctions to nanostructured bulk materials. Nanoscale Energy Transport is a valuable reference for researchers in physics, materials, mechanical and electrical engineering, and it provides an excellent resource for graduate students.

Download or read book Nanoscale Energy Transport and Conversion written by Gang Chen and published by Oxford University Press. This book was released on 2005-03-03 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a graduate level textbook in nanoscale heat transfer and energy conversion that can also be used as a reference for researchers in the developing field of nanoengineering. It provides a comprehensive overview of microscale heat transfer, focusing on thermal energy storage and transport. Chen broadens the readership by incorporating results from related disciplines, from the point of view of thermal energy storage and transport, and presents related topics on the transport of electrons, phonons, photons, and molecules. This book is part of the MIT-Pappalardo Series in Mechanical Engineering.

Download or read book Thermal Transport in Semiconductors written by Pol Torres Alvarez and published by Springer. This book was released on 2018-06-28 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starting from a broad overview of heat transport based on the Boltzmann Transport Equation, this book presents a comprehensive analysis of heat transport in bulk and nanomaterials based on a kinetic-collective model (KCM). This has become key to understanding the field of thermal transport in semiconductors, and represents an important stride. The book describes how heat transport becomes hydrodynamic at the nanoscale, propagating very much like a viscous fluid and manifesting vorticity and friction-like behavior. It introduces a generalization of Fourier’s law including a hydrodynamic term based on collective behavior in the phonon ensemble. This approach makes it possible to describe in a unifying way recent experiments that had to resort to unphysical assumptions in order to uphold the validity of Fourier’s law, demonstrating that hydrodynamic heat transport is a pervasive type of behavior in semiconductors at reduced scales.

Download or read book 21st Century Nanoscience A Handbook written by Klaus D. Sattler and published by CRC Press. This book was released on 2019-11-21 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date reference is the most comprehensive summary of the field of nanoscience and its applications. It begins with fundamental properties at the nanoscale and then goes well beyond into the practical aspects of the design, synthesis, and use of nanomaterials in various industries. It emphasizes the vast strides made in the field over the past decade – the chapters focus on new, promising directions as well as emerging theoretical and experimental methods. The contents incorporate experimental data and graphs where appropriate, as well as supporting tables and figures with a tutorial approach.

Download or read book Phonon Focusing and Phonon Transport written by Igor Gaynitdinovich Kuleyev and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-06-08 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monograph is devoted to the investigation of physical processes that govern the phonon transport in bulk and nanoscale single-crystal samples of cubic symmetry. Special emphasis is given to the study of phonon focusing in cubic crystals and its influence on the boundary scattering and lattice thermal conductivity of bulk materials and nanostructures.

Download or read book Lattice Boltzmann Method And Its Application In Engineering written by Zhaoli Guo and published by World Scientific. This book was released on 2013-03-25 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lattice Boltzmann method (LBM) is a relatively new simulation technique for the modeling of complex fluid systems and has attracted interest from researchers in computational physics. Unlike the traditional CFD methods, which solve the conservation equations of macroscopic properties (i.e., mass, momentum, and energy) numerically, LBM models the fluid consisting of fictive particles, and such particles perform consecutive propagation and collision processes over a discrete lattice mesh.This book will cover the fundamental and practical application of LBM. The first part of the book consists of three chapters starting form the theory of LBM, basic models, initial and boundary conditions, theoretical analysis, to improved models. The second part of the book consists of six chapters, address applications of LBM in various aspects of computational fluid dynamic engineering, covering areas, such as thermo-hydrodynamics, compressible flows, multicomponent/multiphase flows, microscale flows, flows in porous media, turbulent flows, and suspensions.With these coverage LBM, the book intended to promote its applications, instead of the traditional computational fluid dynamic method.

Download or read book Frontiers in Thermal Transport and Energy Conversion written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2020-03-13 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal transport and energy conversion has remained an active field for at least 200 years, with numerous opportunities for discoveries and new applications. Recently, experiments have advanced researchers' understanding of basic physics, and how new discoveries might translate into applications in energy, materials, quantum technologies, and other areas. The National Academies convened a workshop on April 11, 2019 to identify and assess the frontier of current research in the field of thermal transport and energy conversion. Discussions involved topics related to thermal transport and quasi-particle hydrodynamics, thermal transport beyond the quasiparticle paradigm, the thermal hall effect from neutral spin excitations in frustrated quantum magnets, quantization of the thermal hall conductivity at small hall angles, and thermal spin transport, including spin-seebeck and magnon drag effects. These topics were strategically selected with the goal of uncovering key challenges, opportunities, and issues in order to guide future efforts and investments to advance the field. This publication offers a condensed summary of the discussions and presentations from the workshop, which was unclassified and open to the public.

Download or read book Synthesis Modelling and Characterization of 2D Materials and their Heterostructures written by Eui-Hyeok Yang and published by Elsevier. This book was released on 2020-06-19 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis, Modelling and Characterization of 2D Materials and Their Heterostructures provides a detailed discussion on the multiscale computational approach surrounding atomic, molecular and atomic-informed continuum models. In addition to a detailed theoretical description, this book provides example problems, sample code/script, and a discussion on how theoretical analysis provides insight into optimal experimental design. Furthermore, the book addresses the growth mechanism of these 2D materials, the formation of defects, and different lattice mismatch and interlayer interactions. Sections cover direct band gap, Raman scattering, extraordinary strong light matter interaction, layer dependent photoluminescence, and other physical properties. Explains multiscale computational techniques, from atomic to continuum scale, covering different time and length scales Provides fundamental theoretical insights, example problems, sample code and exercise problems Outlines major characterization and synthesis methods for different types of 2D materials

Download or read book Phonon Transport in Ultrahigh and Ultralow Thermal Conductivity Materials written by Joonsang Kang and published by . This book was released on 2019 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced materials with extreme thermal conductivity are critically important for various technological applications including energy conversion, storage, and thermal management. Low thermal conductivity is needed for thermal insulation and thermoelectric energy harvesting, while high thermal conductivity is desirable for efficient heat spreading in electronics. However, practical application deployments are usually limited by the materials availability in nature. Moreover, understanding the fundamental origins for extreme thermal conductivity still remains challenging. My PhD research focuses on finding new thermal materials and unveiling fundamental phonon transport mechanisms in extreme thermal conductivity matters to push the frontier of thermal science. My dissertation is composed of three topics. The first topic is focused on developing and investigating a new group of ultrahigh conductivity materials. High-quality boron phosphide (BP) and boron arsenide (BAs) crystal are synthesized and measured with thermal conductivities of 460 and 1300 W/mK, respectively. In particular, our result shows that BAs is the best thermal conductor among common bulk metals and semiconductors. To better understand the fundamental origin of such an ultrahigh thermal conductivity, advanced phonon spectroscopy and temperature dependent characterizations are performed. Our measurements, in conjunction with atomistic theory, reveal that, unlike the commonly accepted rule for most materials near room temperature, high-order anharmonicity through the four-phonon process is significant in BA because of its unique band structure. Our result underscores the promise of using BP and BAs for thermal management and develops microscopic understanding of the phonon transport mechanisms. The second topic of my thesis is to investigate phonon transport in ultralow thermal conductivity material with a focus on tin selenide (SnSe). SnSe is a recently discovered material for high performance thermoelectricity. However, the thermal properties of intrinsic SnSe remain elusive in literature. To understand the dominant phonon transport mechanisms for the extremely low thermal conductivity of SnSe, temperature-dependent sound velocity, lattice expansion, and Gr neisen parameter was measured. The measurement result shows that high-order anharmonicity introduces strong phonon renormalization and the ultralow thermal conductivity. The third topic of the thesis is to investigate in-situ dynamic tuning of thermal conductivity in layered materials. A novel device platform based on lithium ion battery is developed to characterize the interactions between ions and phonons of layered materials. We observe a highly reversible modulation and anisotropy of thermal conductivity from phonon scattering introduced by ionic intercalation in the interspacing layers. This study provides a unique approach to explore the fundamental energy transport involving lattices and ions and open up new opportunities in thermal engineering.

Download or read book Non Fourier Heat Conduction written by Alexander I. Zhmakin and published by Springer Nature. This book was released on 2023-07-01 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a broad and well-structured overview of various non-Fourier heat conduction models. The classical Fourier heat conduction model is valid for most macroscopic problems. However, it fails when the wave nature of the heat propagation becomes dominant and memory or non-local spatial effects become significant; e.g., during ultrafast heating, heat transfer at the nanoscale, in granular and porous materials, at extremely high values of the heat flux, or in heat transfer in biological tissues. The book looks at numerous non-Fourier heat conduction models that incorporate time non-locality for materials with memory, such as hereditary materials, including fractional hereditary materials, and/or spatial non-locality, i.e. materials with a non-homogeneous inner structure. Beginning with an introduction to classical transport theory, including phase-lag, phonon, and thermomass models, the book then looks at various aspects of relativistic and quantum transport, including approaches based on the Landauer formalism as well as the Green-Kubo theory of linear response. Featuring an appendix that provides an introduction to methods in fractional calculus, this book is a valuable resource for any researcher interested in theoretical and numerical aspects of complex, non-trivial heat conduction problems.

Download or read book Mesoscopic Theories of Heat Transport in Nanosystems written by Antonio Sellitto and published by Springer. This book was released on 2016-02-03 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents generalized heat-conduction laws which, from a mesoscopic perspective, are relevant to new applications (especially in nanoscale heat transfer, nanoscale thermoelectric phenomena, and in diffusive-to-ballistic regime) and at the same time keep up with the pace of current microscopic research. The equations presented in the book are compatible with generalized formulations of nonequilibrium thermodynamics, going beyond the local-equilibrium. The book includes six main chapters, together with a preface and a final section devoted to the future perspectives, as well as an extensive bibliography.

Download or read book Advances in Understanding Thermal Effects in Rubber written by Gert Heinrich and published by Springer Nature. This book was released on with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phonon Transport in Barium Titanate and Rutile written by Alexander Johan Hendrik Mante and published by . This book was released on 1970 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermal Behaviour and Applications of Carbon Based Nanomaterials written by Dimitrios V. Papavassiliou and published by Elsevier. This book was released on 2020-04-15 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanocomposites with Carbon-based nanofillers (e.g., carbon nanotubes, graphene sheets and nanoribbons etc.) form a class of extremely promising materials for thermal applications. In addition to exceptional material properties, the thermal conductivity of the carbon-based nanofillers can be higher than any other known material, suggesting the possibility to engineer nanocomposites that are both lightweight and durable, and have unique thermal properties. This potential is hindered by thermal boundary resistance (TBR) to heat transfer at the interface between nanoinclusions and the matrix, and by the difficulty to control the dispersion pattern and the orientation of the nanoinclusions. Thermal Behaviour and Applications of Carbon-Based Nanomaterials: Theory, Methods and Applications explores heat transfer in nanocomposites, discusses techniques predicting and modeling the thermal behavior of carbon nanocomposites at different scales, and methods for engineering applications of nanofluidics and heat transfer. The chapters combine theoretical explanation, experimental methods and computational analysis to show how carbon-based nanomaterials are being used to optimise heat transfer. The applications-focused emphasis of this book makes it a valuable resource for materials scientists and engineers who want to learn more about nanoscale heat transfer. Offers an informed overview of how carbon nanomaterials are currently used for nanoscale heat transfer Discusses the major applications of carbon nanomaterials for heat transfer in a variety of industry sectors Details the major computational methods for the analysis of the thermal properties of carbon nanomaterials