Growth and structural characterization of InN/In2O3 coaxial nanocables

A synthesis route to coaxial nanocables has been developed using low dissociation temperature of InN and high melting point of In2O3. InN/In2O3 coaxial nanocables were successfully synthesized by a reaction of the mixture of In and In2O3 powder with a constant flowing ammonia atmosphere through two-stage. High-resolution transmission electron microscopy observations demonstrated that the nanocable consists of wurtzite InN nanowire core, In2O3 outer shell separated in the radial direction. The InN/In2O3 coaxial nanocables were 20–80 nm in diameter and up to several tens of micrometers in length. It is proposed that the low dissociation temperature property of InN material acts as an important role to form In2O3 protecting layers which coated the surface of InN nanowires and high melting point of In2O3 prevent InN to further dissociate. The method results in high purity, and high reproducibility of the InN/In2O3 nanocable-structures.