Issue 3, 2018

Minimum thermal conductivity in the context of diffuson-mediated thermal transport

Abstract

A model for the thermal conductivity of bulk solids is proposed in the limit of diffusive transport mediated by diffusons as opposed to phonons. This diffusive thermal conductivity, κdiff, is determined by the average energy of the vibrational density of states, ℏωavg, and the number density of atoms, n. Furthermore, κdiff is suggested as an appropriate estimate of the minimum thermal conductivity for complex materials, such that (at high temperatures): Image ID:c7ee03256k-t1.gif. A heuristic finding of this study is that the experimental ωavg is highly correlated with the Debye temperature, allowing κdiff to be estimated from the longitudinal and transverse speeds of sound: Image ID:c7ee03256k-t2.gif. Using this equation to estimate κmin gives values 37% lower than the widely-used Cahill result and 18% lower than the Clarke model for κmin, on average. This model of diffuson-mediated thermal conductivity may thus help explain experimental results of ultralow thermal conductivity.

Graphical abstract: Minimum thermal conductivity in the context of diffuson-mediated thermal transport

Article information

Article type
Paper
Submitted
14 Nov 2017
Accepted
01 Feb 2018
First published
01 Feb 2018

Energy Environ. Sci., 2018,11, 609-616

Minimum thermal conductivity in the context of diffuson-mediated thermal transport

M. T. Agne, R. Hanus and G. J. Snyder, Energy Environ. Sci., 2018, 11, 609 DOI: 10.1039/C7EE03256K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements