The Observation of Spin Seebeck Effect of Hybrid Structure in Bulk Sintering Polycrystalline of Yttrium Iron Oxide (Y3Fe5O12)/Pt

In this article, we report the observation of spin Seebeck effect (SSE) of hybrid structure in bulk sintering polycrystalline of yttrium iron oxide (Y3Fe5O12, YIG)/Pt. The bulk YIG polycrystalline is prepared by solid press mechanic and then coated with Pt 10 nm thickness. The voltage of inverse spin Hall effect (VISHE) in Pt/YIG polycrystalline is detected by in plane magnetization configuration (IM) and then filter out the anomalous Nernst effect (ANE) by perpendicular magnetization configuration (PM). The results show that the VISHE signal can be observed in bulk YIG polycrystalline. In addition, the efficiency of spin injection from YIG to Pt is compared between Pt/YIG single crystal and bulk polycrystalline of hybrid structure. The VISHE signal of Pt/YIG single crystal and bulk polycrystalline are 197.61 nV/K and 23.22 nV/K, respectively. The VISHE voltage of YIG single crystal is higher than bulk polycrystalline about 9 times. Whereas, the porous size in bulk YIG polycrystalline of solid press is determined around 214 ± 81 nm but it cannot detect in YIG single crystal. Thus, the porous size and surface roughness between YIG and Pt might be the major role of the spin current (Js) transfer.