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Related papers: Cross-plane heat conduction in thin solid films

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Tuning thermal transport in nanostructured materials is a powerful approach to develop high-efficiency thermoelectric materials. Using a recently developed approach based on the phonon mean free path dependent Boltzmann transport equation,…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 Giuseppe Romano , Jeffrey C. Grossman

The impact of boundary scattering on non-diffusive thermal relaxation of a transient grating in thin membranes is rigorously analyzed using the multidimensional phonon Boltzmann equation. The gray Boltzmann simulation results indicate that…

Quasiparticle theory gives a local relation between heat current and temperature gradient, provided the quasiparticle mean free path is smaller than the scale of variation of temperature. When mean free paths are comparable to sample size,…

Mesoscale and Nanoscale Physics · Physics 2013-08-14 Philip B. Allen

Nanostructured materials exhibit low thermal conductivity because of the additional scattering due to phonon-boundary interactions. As these interactions are highly sensitive to the mean free path (MFP) of a given phonon mode, MFP…

Materials Science · Physics 2016-01-13 Giuseppe Romano , Keivan Esfarjani , David A. Strubbe , David Broido , Alexie M. Kolpak

At micro- to nano-scales, classical size effects in heat conduction play an important role in suppressing the thermal transport process. Such effects occur when the characteristic lengths become commensurate to the mean free paths (MFPs) of…

Applied Physics · Physics 2019-05-08 Qing Hao , Yue Xiao , Qiyu Chen

Steady-state thermal transport in nanostructures with dimensions comparable to the phonon mean-free-path is examined. Both the case of contacts at different temperatures with no internal heat generation and contacts at the same temperature…

Mesoscale and Nanoscale Physics · Physics 2017-03-08 Jan Kaiser , Tianli Feng , Jesse Maassen , Xufeng Wang , Xiulin Ruan , Mark Lundstrom

The relaxation of a spatially sinusoidal temperature perturbation in a dielectric crystal at a temperature comparable to or higher than the Debye temperature is investigated theoretically. We assume that most phonons contributing to the…

Materials Science · Physics 2011-12-12 A. A. Maznev , Jeremy A. Johnson , Keith A. Nelson

Efficient thermal management is essential for the reliability of modern power electronics, where increasing device density leads to severe heat dissipation challenges. However, in thin-film systems, thermal transport is often compromised by…

It is generally understood that Fourier's law does not describe ballistic phonon transport, which is important when the length of a material is similar to the phonon mean-free-path. Using an approach adapted from electron transport, we…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 Jesse Maassen , Mark Lundstrom

Sub-micron-thick layers of hexagonal boron nitride (hBN) exhibit high in-plane thermal conductivity, useful optical properties, and serve as dielectric encapsulation layers with low electrostatic inhomogeneity for graphene devices. Despite…

Phonon heat conduction over length scales comparable to their mean free paths is a topic of considerable interest for basic science and thermal management technologies. Although the failure of Fourier's law beyond the diffusive regime is…

Materials Science · Physics 2019-08-28 Chengyun Hua , Lucas Lindsay , Xiangwen Chen , Austin Minnich

We present a new method for predicting effective thermal conductivity ($\kappa_{\textrm{eff}}$) in materials, informed by ${ab\,initio}$ material property simulations. Using the Boltzmann transport equation in a Self-Adjoint Angular Flux…

Materials Science · Physics 2019-08-22 Jackson R. Harter , Aria Hosseini , Todd. S. Palmer , P. Alex Greaney

We present an innovative contactless method suitable to study in-plane thermal transport based on beam-offset frequency-domain thermoreflectance using a one-dimensional heat source with uniform power distribution. Using a one-dimensional…

In this article, we are proposing a thorough analysis of the cross, and the in-plane thermal conductivity of thin-film materials based on the 3$\omega$ method. The analysis accommodates a 2D mathematical heat transfer model of a…

Applied Physics · Physics 2020-07-02 Daxi Zhang , Amir Behbahanian , Nicholas A. Roberts

Transient heat dissipation in close-packed quasi-2D nanoline and 3D nanocuboid hotspot systems is studied based on phonon Boltzmann transport equation. It is found that, counter-intuitively, the heat dissipation efficiency is not a…

Mesoscale and Nanoscale Physics · Physics 2022-07-20 Chuang Zhang , Lei Wu

In this paper, we examine the application of an ideal phonon-hydrodynamic material as the heat transfer medium between two non-hydrodynamic contacts with a finite temperature difference. We use the integral-equation approach to solve a…

Materials Science · Physics 2018-11-12 Runqing Yang , Shengying Yue , Bolin Liao

Thermal conductivity in dielectric crystals is the result of the relaxation of lattice vibrations described by the phonon Boltzmann transport equation. Remarkably, an exact microscopic definition of the heat carriers and their relaxation…

Materials Science · Physics 2016-10-26 Andrea Cepellotti , Nicola Marzari

The Boltzmann transport equation for phonons is recast directly in terms of the heat-flux by means of iteration followed by truncation at the second order in the spherical harmonic expansion of the distribution function. This procedure…

Mesoscale and Nanoscale Physics · Physics 2015-10-28 Ashok T. Ramu , John E. Bowers

This work demonstrates a first-principles-based approach to obtaining finite temperature thermal and electronic transport properties which can be employed to model and understand mesoscale structural evolution during electronic, magnetic,…

The cross-plane (across-layers) phonon thermal transport of five diverse, layered semiconductors is investigated by accounting for higher-order four-phonon scattering, phonon renormalization, and multi-channel thermal transport. For…

Materials Science · Physics 2023-11-07 Amey G. Gokhale , Ankit Jain