2025/01/17 by Koichi Oyanagi, Oyanagi, Koichi, H. Sepehri‐Amin +21
Materials Science · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Heusler alloys: electronic and magnetic properties #Materials Science (cond-mat.mtrl-sci) #Topological Materials and Phenomena
paper · doi:10.48550/arxiv.2501.09965
openalex publication_date 2025/01/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This study reports the observation of the large anomalous Nernst effect in polycrystalline ferromagnetic Co2MnGa (CMG) slabs prepared by a spark plasma sintering method. By optimizing the sintering conditions, the anomalous Nernst coefficient reaches ~7.5 μV K-1 at room temperature, comparable to the highest value reported in the single-crystalline CMG slabs. Owing to the sizable anomalous Nernst coefficient and reduced thermal conductivity, the dimensionless figure of merit in our optimized CMG slab shows the record-high value of ~8×10-4 at room temperature. With the aid of the nano/microstructure characterization and first-principles phonon calculation, this study discusses the dependence of the transport properties on the degree of crystalline ordering and morphology of crystal-domain boundaries in the sintered CMG slabs. The results reveal a potential of polycrystalline topological materials for transverse thermoelectric applications, enabling the construction of large-scale modules.