Large anomalous Nernst effect and nodal plane in an iron-based kagome ferromagnet.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35030028.
- Also identified by DOI 10.1126/sciadv.abk1480 and PMC identifier 8759748.
- Licence recorded as CC BY-NC.
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Abstract
Anomalous Nernst effect (ANE), converting a heat flow to transverse electric voltage, originates from the Berry phase of electronic wave function near the Fermi energy <i>E</i><sub>F</sub>. Thus, the ANE provides a sensitive probe to detect a topological state that produces large Berry curvature. In addition, a magnet that exhibits a large ANE using low-cost and safe elements will be useful to develop a novel energy harvesting technology. Here, we report our observation of a high ANE exceeding 3 microvolts per kelvin above room temperature in the kagome ferromagnet Fe<sub>3</sub>Sn with the Curie temperature of 760 kelvin. Our theoretical analysis clarifies that a “nodal plane” produces a flat hexagonal frame with strongly enhanced Berry curvature, resulting in the large ANE. Our discovery of the large ANE in Fe<sub>3</sub>Sn opens the path for the previously unexplored functionality of flat degenerate electronic states and for developing flexible film thermopile and heat current sensors.