Quantum Anomalous Hall Effect with Tunable Chern Number in Intrinsic High-Temperature Ferromagnetic Monolayer MnSbO₃

Quantum anomalous Hall effect (QAHE) offers an intriguing platform for low-dissipation device applications, garnering significant attention. This study, based on first-principles calculations, predicts that monolayer MnSbO3 is an intrinsic high-temperature ferromagnetic material with a Curie temperature of 443 K. Its band structure exhibits the characteristics of a Dirac half-metal. Upon incorporating spin–orbit coupling (SOC), a topologically nontrivial bandgap emerges, enabling the realization of QAHE with tunable Chern numbers through the control of the magnetization direction. When the magnetization is oriented along the x-axis, the material preserves partial mirror symmetry, resulting in a Chern number of C = ±1. Reorienting the magnetization along the z-axis, a higher Chern number of C = ±3 is achieved. Under biaxial strain, not only a large bandgap of 47 meV is achieved, which is feasible to be realized experimentally, but the magnetic anisotropy energy (MAE) is also effectively modulated, enabling magnetization reorientation to achieve high Chern numbers. Finally, we construct a MnSbO3–BN heterostructure and investigate its feasibility for experimental synthesis under tensile strain. The research provides theoretical support and potential applications for realizing high-temperature QAHE with tunable Chern numbers and advancing the development of topological materials.