Temperature dependence of the electrical and thermal transport in FeCo/Cu/Ni80Fe20 spin valves

Creating spin current under temperature gradient in magnetic devices has resulted in a new emerging field of spin caloritronics, but extraction of material parameters i.e. Seebeck coefficient and interpretation of thermal transport characteristics are still great challenges due to the thermal contact effect, especially in a wide temperature range. Because the heat-driven voltages do not depend on the change of magnetic states in spin valve, this could be used to obtain the accurate temperature difference applied on sample and exclude the thermal contact effect. Based on this calibration, the electrical and thermal spin transport behaviors in the in-plane FeCo/Cu/FeNi spin valve were systematically studied with various temperature. We observed that the Seebeck coefficients of spin valve was negative and spin-dependent Seebeck coefficient was proportional to the asymmetry parameter in a wide temperature range from 100 to 300 K, indicating that the spin-dependent thermal transports are closely related with electrical transports in the in-plane spin valve.