Load characteristics of magnetization-dependent transverse thermoelectric generation in GdFeCo ferrimagnetic alloy thin films

Abstract We evaluated the thermoelectric voltage and electric power induced by the transverse and longitudinal thermoelectric generation, along with their load resistance characteristics, by measuring the load voltage in remanent magnetization states of a perpendicularly magnetized GdFeCo ferrimagnetic alloy thin film. Various load resistances were connected transversely and longitudinally to the temperature gradient. Our results showed that the load voltage induced by thermoelectric generation varied with load resistance. Additionally, the sign of the transverse load voltage reversed with the reversal of magnetization. The electric power generated thermoelectrically exhibited load dependency, reaching a local maximum. These behaviors can be qualitatively explained by the load characteristics of the power supply circuit, where polarity changes with the direction of remanent magnetization. In conclusion, we demonstrated the extraction of electric power via thermoelectric generation in a GdFeCo ferrimagnetic thin film. These observations suggest that using magnetic materials can provide new functionality for thermoelectric generators.