We report on the growth of coaxial InxGa1 (-) N-x/GaN nanowires (NWs) on Si(111) substrates by using pulsed flow metalorganic chemical vapor deposition. The coaxial InxGa1 (-) N-x/GaN NWs were grown by a two step process in which the core (GaN) structure was grown at a higher temperature followed by the shell (InxGa1 (-) N-x) structure at a lower temperature. Dense and well-oriented coaxial InxGa1 (-) N-x/GaN NWs were grown with an average diameter and length of about 300 +/- 50 nm and 1.5-2.0 mu m, respectively. The coaxial InxGa1 (-) N-x/GaN NW was confirmed by cathodoluminescence mapping and high-resolution transmission electron microscopy. It is proposed that the critical dissociation of precursors at an elevated growth temperature can lead to a clear formation of an outer-shell in coaxial InxGa1 (-) N-x/GaN NWs. (C) 2012 Elsevier B. V. All rights reserved.