Abstract
X-ray diffraction (XRD), scanning electron microscopy (SEM), density thermoelectric power, and transport properties of the as prepared nanocrystalline NaxV(2)O(5)center dot nH(2)O xerogel thin films (0 6 x 6 20 mol%) were investigated. These films have been produced by the sol-gel technique (colloidal route). XRD revealed that the samples are highly orientated nanocrystals and all samples show almost the same X-ray diffraction patterns with different lattice constant. The particle size was found to be about 7.5 nm. In SEM the porosity and microstructure of NaxV(2)O(5)center dot nH(2)O thin films can be tuned effectively by adjusting the concentration of the Na1+ ions in the electrolytic solution. The density of the samples increases with increasing Na-content. The samples are n-type semiconductor according to the thermoelectric power. The thermoelectric power increases with increasing Na-content. The electrical conductivity shows that all samples are semiconductor and it increases with increasing Na-content. The activation energy decreases with increasing Na-content. The conduction was confirmed to obey the non-adiabatic small polaron hopping. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.