Large anomalous Nernst effect in non-crystalline Gd-Fe ferrimagnetic alloy films for flexible thermoelectric applications

Abstract: The anomalous Nernst effect (ANE), a heat-charge conversion mechanism based on a magnetic metal, has been extensively studied for application in thin thermoelectric devices. The low magnetization and fabrication at room temperature are important for flexible ANE thermoelectric devices on plastic substrates. Therefore, we investigated the ANE in ferrimagnetic GdxFe100-x films with low magnetization in this study by systematically varying the Gd composition x. Although the Gd33Fe67 film with a Gd composition close to magnetic compensation composition exhibited very low magnetization, an ANE coefficient |S_ANE| of 2.13 uV/K was obtained, which is close to the highest value reported thus far. Finally, we demonstrated the ANE in a Gd33Fe67 film deposited on a flexible sheet. A sufficient ANE voltage was obtained while maintaining the flexibility of the sample, indicating the potential application of this material in thermoelectric devices exploiting the ANE of Gd-Fe films.