X-ray diffraction patterns, scanning electron microscopy images, and transmission electron microscopy (TEM) images showed that one-dimensional GaN nanorods grown on Si (111) substarates by using hydride vapor phase epitaxy had crystalline wurzite structures and were preferentially oriented along the [0 0 0 1] direction. The high-resolution TEM (HRTEM) images showed that the side facet planes of the tip region for the GaN nanorods consisted of {(1) over bar1 0 0}, {(1) over bar1 0 2}, and {(1) over bar 1 0 3} planes. The structural properties of the GaN nanorods were significantly affected by the gas-mixing and the substrate temperatures in the final growth zone. (C) 2008 Elsevier B.V. All rights reserved.