2026-07-21 物質・材料研究機構,東京大学,科学技術振興機構
図: 従来型スピンゼーベック素子とトランススケール・スピンゼーベック素子の概念図。従来構造(a)では、スピン流の寄与は磁性体と金属の界面近傍のみに現れる(b)。一方、今回開発した複合体(c)では、金属が材料内部に三次元的に分散しており(d)、バルク全体を使ったスピン流生成とスピンゼーベック効果による熱電変換が可能となる(e)。
＜関連情報＞
- https://www.nims.go.jp/press/2026/07/202607210.html
- https://www.nature.com/articles/s41467-026-75232-0
磁性絶縁体に基づくナノ構造バルク複合材料におけるスケールを超えたスピンゼーベック効果 Trans-scale spin Seebeck effect in nanostructured bulk composites based on magnetic insulator
Sang J. Park,Keisuke Hirata,Hossein Sepehri-Amin,Fuyuki Ando,Takamasa Hirai & Ken-ichi Uchida
Nature Communications Published:21 July 2026
DOI:https://doi.org/10.1038/s41467-026-75232-0
Abstract
The spin Seebeck effect enables thermoelectric conversion through thermally generated spin currents in magnetic materials, offering a promising transverse geometry for scalable devices. However, conventional spin Seebeck devices are confined to nanoscale thin-film architectures, with significantly restricted output power due to the intrinsic constraints of spin and magnon diffusion lengths. Here, we demonstrate a trans-scale spin Seebeck effect using nanostructured bulk composites composed of Pt-coated yttrium iron garnet powders fabricated via dynamic powder sputtering and low-temperature sintering. The resulting three-dimensional composites exhibit continuous Pt channels and robust mechanical integrity. Transverse thermoelectric measurements reveal isotropic spin Seebeck signals at the bulk scale. Power analysis indicates that the three-dimensional architecture enables scalable volumetric thermoelectric power generation beyond diffusion-limited thin-film spin Seebeck geometries. This work establishes a scalable platform for spin Seebeck thermoelectric conversion, bridging nanoscale spin caloritronics with macroscopic device integration.
