Turning up the heat to create new nanostructured metals

Scientists have developed a new approach for making metal-metal composites and porous metals with a 3-D interconnected "bicontinuous" structure in thin films at size scales ranging from tens of nanometers to microns. Metallic materials with this sponge-like morphology -- characterized by two coexisting phases that form interpenetrating networks continuing over space -- could be useful in catalysis, energy generation and storage, and biomedical sensing. Called thin-film solid-state interfacial dealloying (SSID), the approach uses heat to drive a self-organizing process in which metals mix or de-mix to form a new structure. The scientists used multiple electron- and x-ray-based techniques ("multimodal analysis") to visualize and characterize the formation of the bicontinuous structure.