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 ANE) and small saturation magnetization. This motivated us to investigate the effect of Al substitution of Fe on ANE and found S ANE = 3.4 μV K-1 in Fe81Al19 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.