Ferrovalley two-dimensional metal–organic frameworks with large out-of-plane magnetic anisotropy and valley polarization

Valleytronic devices show great promise for next-generation information technology, yet their practical development is limited by the lack of intrinsic ferrovalley materials. To address this issue, we propose an efficient bottom-up strategy to design high-performance two-dimensional (2D) ferrovalley materials, constructing a series of hexagonal metal–organic frameworks (MOFs) from trigonal bipyramidal TMCu4 magnetic clusters (TM = Ta, W, Os, Ir, Re) and organic linker C4H4P2. First principles calculations confirm that these 2D MOFs feature large magnetic anisotropy and robust spontaneous valley polarization. In particular, both freestanding and h-BN-supported Ir–W-based MOFs exhibit large Berry curvatures with opposite signs and distinct magnitudes at the K and K′ valleys. Furthermore, we demonstrate that the intrinsic valley polarization can be reversibly switched by external electric and magnetic fields, enabling potential applications in valleytronic devices.