Abstract
The electronic flat band in kagome lattice, arising from strong localization of electrons, provides an ideal platform to materialize both electron-correlated and topological phenomena. However, kagome metals with flat bands have been rarely explored in terms of utilizing its distinct characteristics for device functionality. Here, we report on the room-temperature ferrimagnet Co3Mo films with a Co-kagome lattice as potential magnetic devices. By applying band structure calculations and angle-resolved photoemission spectroscopy (ARPES), we discovered that the Co-kagome flat bands are located close to Fermi energy and magnetocrystalline anisotropy via spin-orbit interaction plays a key role for perpendicular magnetic anisotropy (PMA), resulting in characteristic small magnetization, large coercive field, and anomalous Hall effect. Furthermore, Pt-substitution in Co3Mo1-xPtx films dramatically enhances the PMA, highlighting the unique spin-orbit physics of the Co-kagome lattice. These findings establish Co3Mo as a promising platform for demonstration of magnetic devices based on topological concepts and for advancing flat-band physics.
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The data that support the findings of this study are available from the corresponding author upon request.
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Acknowledgements
The authors thank M. Osada and T. Terada for technical help. STEM observations were carried out with the cooperation of Y. Kodama and T. Konno of Analytical Research Core for Advanced Materials, Institute for Materials Research, Tohoku University. The authors thank J. Okabayashi for XMCD measurements. This study was partially supported by JST-CREST (JPMJCR18T1 and JPMJCR18T2), JST-FOREST (No. JPMJFR223Y), and JSPS KAKENHI (22H00288, 25H01247, 21K13875).
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A.T. conceived the project. K.I. fabricated and characterized the films with the support of K.F. K.N. and Y.M. conducted the ab initio calculation. K.I. and K.F. carried out the magnetization measurement with the support of T.Y. and T. Seki. S.S., D.S., H.K. and T. Sato. carried out the ARPES measurement and analysis of the data. K.I. and A.T. wrote the manuscript with input from all the authors.
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Communications Materials thanks Jian-Qiao Meng and the other anonymous reviewer(s) for their contribution to the peer review of this work. A peer review file is available.
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Ishida, K., Fujiwara, K., Nakazawa, K. et al. Room-temperature perpendicular-anisotropic ferrimagnet Co3Mo mediated by cobalt-kagome flat band. Commun Mater (2026). https://doi.org/10.1038/s43246-026-01131-y
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DOI: https://doi.org/10.1038/s43246-026-01131-y
