We propose the van der Waals layered ternary transition metal chalcogenides ${\mathrm{FeTa}X}_2$ ($X=\mathrm{S}$, Se, Te) as a new family of ferrimagnetic quantum anomalous Hall insulators with a sizable bulk gap and high Chern number $\mathcal{C}=-2$. The magnetic order arises primarily from Fe atoms, whose strong ferromagnetic exchange induces moments on neighboring Ta sites. The large topological gap originates from a strong $s\text{−}d$-type band inversion between spin-down Ta $d_{z^2}$ and $d_{xy}$ orbitals near the Fermi level—a mechanism unique to $d$-orbital systems. Remarkably, the Curie temperature of monolayer ${\mathrm{FeTa}X}_2$ is predicted to significantly exceed that of monolayer ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$. Furthermore, both the Curie temperature and topological gap scale positively with the spin-orbit coupling strength of the $d$ electrons, suggesting a common physical origin. These findings, if realized experimentally, could open new avenues for the research and application of topological quantum physics.

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• Electronic structure
• Quantum anomalous Hall effect
• Topological insulators
• Ferrimagnets
• Iron-based superconductors
• Topological materials
• First-principles calculations