Rayleigh-instability-driven simultaneous morphological and compositional transformation from Co nanowires to CoO octahedra

Abstract

Arrays of regularly distributed CoO nano-octahedra are obtained by annealing Co nanowires at high temperatures. Both the size and the separation distance of the nano-octahedra can be controlled by tuning the annealing temperature. These self-assembled linear arrays of CoO nanocrystals result from the synergetic combination of the morphological transformation due to the intrinsic Rayleigh instability and the phase transformation due to the cobalt oxidation.