Improvement of Mixing Conductance and Spin-Seebeck Effect at Fe Interface Treatment

In the previous work, it is reported that the Spin-Seebeck effect (SSE), which refer to the generation of a spin current from a temperature gradient, can be enhanced by Fe interface treatment. Here, we investigated the Fe thickness (d Fe) dependency of spin-Seebeck voltage (V SSE) and mixing conductance (g r) in Pt/Fe/Bi:YIG/SGGG system. As a result, magnitude of V SSE had a peak at d Fe â‰" 1 ML (monolayer , â‰" 0.3 mm), and also increase of g r was saturated at this point. It suggests that V SSE increase with increasing g r when d Fe is smaller than 1.0 ML. For the case in which d Fe is larger than 1.0ML, however, V SSE decreases due to a spin current decay in Fe layer with a constant g r. These experimental results are consistent with previous theoretical works.