Large Anomalous Nernst Effects at Room Temperature in Fe3Pt Thin Films

作者：Minghang Li, H. Pi, Yunchi Zhao, Ting Lin, Qinghua Zhang, Xinzhe Hu, C. Xiong, Z. Qiu, Lichen Wang, Ying Zhang, J. Cai, Wuming Liu, Jirong Sun, F. Hu, Lin Gu, H. Weng, Quansheng Wu, Shouguo Wang, Yunzhong Chen, Bao-ben Shen · 发表于：Advances in Materials · 年份：2023 · DOI：10.1002/adma.202301339 · 被引用次数：44 · 研究领域：Medicine

Heat current in ferromagnets can generate a transverse electric voltage perpendicular to magnetization, known as anomalous Nernst effect (ANE). ANE originates intrinsically from the combination of large Berry curvature and density of states near the Fermi energy. It shows technical advantages over the conventional longitudinal Seebeck effect in converting waste heat to electricity due to its unique transverse geometry. However, materials showing giant ANE remain to be explored. Herein, a large ANE thermopower of Syx ≈ 2 µV K−1 at room temperature in ferromagnetic Fe3Pt epitaxial films is reported, which also show a giant transverse thermoelectric conductivity of αyx ≈ 4 A K−1 m−1 and a remarkable coercive field of 1300 Oe. The theoretical analysis reveals that the strong spin‐orbit interaction in addition to the hybridization between Pt 5d and Fe 3d electrons leads to a series of distinct energy gaps and large Berry curvature in the Brillouin zone, which is the key for the large ANE. These results highlight the important roles of both Berry curvature and spin‐orbit coupling in achieving large ANE at zero magnetic field, providing pathways to explore materials with giant transverse thermoelectric effect without an external magnetic field.