In Situ Topological Dealloying Enables Atomically Coupled Metal‐Oxide Heterostructures

Metal-oxide heterostructures are central to energy conversion and electronic devices because interfaces can modulate the configuration coupling among charge, spin, and orbit. However, conventional synthesis routes suffer from structural incompatibility and weak coupling, which hinder the universal construction of atomically coupled metal-oxide heterointerfaces. Here, we develop an in situ topological dealloying strategy to construct metal-oxide heterostructures with atomically interconnected interfaces. This strategy can be broadly applied to perovskite, spinel, columbite, and vanadate oxides, which enables the spontaneous formation of high-density magnetic nanoalloys embedded within dielectric oxide matrices. Direct nanoscale visualizations of electric and magnetic fields reveal the coexistence of interfacial charge polarization and vortex-like spin textures. These emergent dielectric and magnetic behaviors arise from atomically interfacial hybridization that mediates strong charge-spin interactions. When integrated into flexible architectures, these heterostructures exhibit broadband GHz-frequency absorption (effective absorption bandwidth up to 6.6 GHz at 3.0 mm), high efficiency, and rapid electromagnetic-to-thermal energy conversion under microwave irradiation. This work establishes a general route to engineer metal-oxide heterostructures for functional applications.