Evolution of a bicontinuous nanostructure via a solid-state interfacial dealloying reaction

The solid dealloying reaction was investigated using (Fe,Cr)-Ni and Mg diffusion couples. Ni selectively reacted with Mg and the remaining Fe and Cr formed various topologies. An etching treatment provided interconnected Fe-Cr alloy with a ligament width below 200 nm, which is about one order of magnitude finer than that obtained for dealloying with Mg melt. The formation of ordered single-crystal nanofilaments at the dealloying front suggests that the topology evolved via the recently proposed interfacial spinodal decomposition and diffusion-coupled growth mechanism.