The 3‐method for thermal conductivity measurements in a bottom heater geometry

Abstract

AbstractIn this article, we investigate a bottom heater geometry configuration for the 3‐method, to determine the thermal conductivity of bulk‐like materials and thin covering layer materials. By finite element simulations, the temperature oscillations due to AC Joule heating are calculated in the time domain. Based on these calculations an understanding is developed for the dependence of the temperature amplitude on thermal conductivity and the chosen geometries. Since no closed form solution exists for these configurations, we developed a new evaluation methodology in order to identify the thermal conductivity of the investigated material. We discuss the determination of the cross‐plane thermal conductivity of materials in bulk and thin film geometries and verify the obtained result by an experiment, where a SrTiO thin film is deposited on top of a Pt heater.