Heat flux sensing by anomalous Nernst effect in Fe–Al thin films on a flexible substrate

Abstract

We performed a numerical analysis of the material parameters required for realizing a heat flux sensor exploiting the anomalous Nernst effect (ANE). The results showed the importance of high thermopower of ANE ($S_{\text{ANE}}$) and small saturation magnetization. This motivated us to investigate the effect of Al substitution of Fe on ANE and found $S_{\text{ANE}} =$ 3.4 $\mu$V/K in Fe$_{81}$Al$_{19}$ because of the dominant intrinsic mechanism. Using this material, we made a prototype ANE-based heat flux sensor on a thin flexible polyimide sheet and demonstrated accurate sensing with it. This study gives important information for enhancing sensor sensitivity.

Topics & Concepts