Room-temperature perpendicular-anisotropic ferrimagnet Co3Mo mediated by cobalt-kagome flat band

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. The electronic flat band in kagome lattices offers a promising platform for exploring electron-correlated and topological phenomena, yet its potential for device functionality remains underexplored. Here, the authors investigate Co₃Mo films, revealing enhanced perpendicular magnetic anisotropy, large coercive field, and anomalous Hall effect mediated by kagome lattice flat bands close to the Fermi level, positioning Co₃Mo as a candidate for topological magnetic devices.