A steady-state thermoreflectance method to measure thermal conductivity

Jeffrey L Braun; David H Olson; John T Gaskins; Patrick E Hopkins

doi:10.1063/1.5056182

A steady-state thermoreflectance method to measure thermal conductivity

Rev Sci Instrum. 2019 Feb;90(2):024905. doi: 10.1063/1.5056182.

Authors

Jeffrey L Braun¹, David H Olson¹, John T Gaskins¹, Patrick E Hopkins¹

Affiliation

¹ Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA.

PMID: 30831683
DOI: 10.1063/1.5056182

Abstract

We demonstrate a steady-state thermoreflectance-based optical pump-probe technique to measure the thermal conductivity of materials using a continuous wave laser heat source. The technique works in principle by inducing a steady-state temperature rise in a material via long enough exposure to heating from a pump laser. A probe beam is then used to detect the resulting change in reflectance, which is proportional to the change in temperature at the sample surface. Increasing the power of the pump beam to induce larger temperature rises, Fourier's law is used to determine the thermal conductivity. We show that this technique is capable of measuring the thermal conductivity of a wide array of materials having thermal conductivities ranging from 1 to >2000 W m^-1 K^-1, in excellent agreement with literature values.