Effect of thermal annealing on the spin Seebeck effect in Pt/Ni81Fe19 at room temperature

The spin Seebeck effect was observed in Pt/Ni81Fe19. Hysteresis-like behavior was discovered, and the saturated voltage was proportional to the temperature gradient. The measured voltage increased as the Pt thickness was decreased, because the injected spin current intensity drastically decreased. Thermal annealing temperature also strongly affected the observed voltage, which was lower at higher thermal annealing temperatures. The anomalous Nernst effect was also observed in Ni81Fe19 films of various thicknesses. The voltage was nearly constant when the Ni81Fe19 film was thicker than 30 nm but drastically decreased for lesser thicknesses.