Abstract
An unusual nanorod growth phenomenon is described. Indium sesquioxide (In 2 O 3 ) nanorods with diameter of 20 nm and length up to several hundreds nanometers were formed on the surface of commercial anodic aluminum oxide (AAO) membranes through calcination of InCl 3 · 4H 2 O at 500°C. The growth of In 2 O 3 in the form of short rods, instead of the particulates commonly encountered in calcination processes, was believed to be induced by the thin frame of the net-shape structure on the AAO membrane surface. The particulate form of In 2 O 3 was obtained in the absence of the net-shape structure or in the presence of non-net-shape structure. Photoluminescence (PL) measurement at room temperature showed two emission peaks at 405 and 462 nm, with the former attributable to the near band edge emission of In 2 O 3 and the latter resulting from the common oxygen deficiency in In 2 O 3 . X-ray diffraction and electron diffraction patterns indicated that the In 2 O 3 nanorods were in a polycrystalline cubic phase. The unusual growth mechanism of In 2 O 3 nanorods offers a simple and convenient alternative synthetic route for one-dimensional structures of In 2 O 3 and possibly other materials. © 2005 Elsevier B.V. All rights reserved.