Eur. Phys. J. D 43, 295-298 (2007)
https://doi.org/10.1140/epjd/e2007-00101-2

Structure and electrical conduction of WO₃ nanorods epitaxially grown on mica

¹ Université Paul Cézanne–Aix Marseille III, Faculté des sciences et techniques, Case 151, 52 avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20, France
² Department of Electronics and Vacuum Physics, Faculty of Mathematics and Physics Charles University, V. Holesovickach 2, 180000 Prague, Czech Republic

Corresponding author: ^a marcel.gillet@l2mp.fr

Received: 25 July 2006
Revised: 2 November 2006
Published online: 24 May 2007

Abstract

Tunsten oxide nanorods are grown on mica substrate in air from WO₃ vapor at 590 °C. They are epitaxially oriented on the substrate in three directions according to the hexagonal symmetry of the mica. Their morphology was investigated by Atomic Force Microscopy (AFM), their structure by Electron Diffraction (ED) and High Resolution Electron Microscopy (HRTEM). The energy dispersive X-ray analysis (EDX) associated with the TEM revealed the presence of potassium in the first step of the nanostructures growth suggesting the formation of a tungsten bronze. According to their thickness the nanorods have a structure either hexagonal or monoclinic. The structural investigations showed that numerous kinds of planar defects parallel to the growth direction are formed. The electrical conduction was analyzed with a Conductive Atomic Force Microscopy (CAFM) method which allows to obtain either an image of the resistance variations along the nanorods or a current-voltage response. The result demonstrates that the WO₃ nanorods form electrically networks suitable for gas sensing experiments.