Thermal insulator transition induced by interface scattering

TL;DR

This paper presents an effective medium model that explains how interface scattering can induce a transition from thermal conduction to insulation in composite materials, aiding the design of materials with tailored thermal properties.

Contribution

The authors develop a new effective medium model incorporating percolation and interface scattering, predicting insulator transitions at high loadings due to interface resistance.

Findings

Model accurately explains experimental thermal conductivity variations.

Predicts sharp decrease in conductivity due to interface scattering.

Suggests potential for designing materials with controlled thermal states.

Abstract

We develop an effective medium model of thermal conductivity that accounts for both percolation and interface scattering. This model accurately explains the measured increase and decrease of thermal conductivity with loading in composites dominated by percolation and interface scattering, respectively. Our model further predicts that strong interface scattering leads to a sharp decrease in thermal conductivity, or an insulator transition, at high loadings when conduction through the matrix is restricted and heat is forced to diffuse through particles with large interface resistance. The accuracy of our model and its ability to predict transitions between insulating and conducting states suggest it can be a useful tool for designing materials with low or high thermal conductivity for a variety of applications.