Abstract
Nickel doped tin oxide (Sn1-xNixO2, where x = 0, 0.05, 0.07 and 0.09) nanoparticles with sub-5 nm size were synthesized using sol-gel method. The structural and compositional analyses were carried out using XRD, FESEM and EDAX Electrical properties were studied using dielectric and impedance spectroscopy at room temperature. XRD analysis indicated the formation of single phase rutile structure of all the samples. The particle size was observed to vary from 5 nm to 2 nm as the nickel content was increased. The XRD and EDAX results corroborated the successful doping of Ni in the SnO2 matrix. The dielectric constant epsilon', epsilon '', loss tangent tan delta and ac conductivity sigma(ac) were studied as a function of frequency and composition and the behaviour has been explained on the basis of Maxwell-Wagner model. Complex impedance analysis which was used to separate the grain and grain boundary contributions to the system suggests the dominance of grain boundary resistance in the doped samples. (C) 2010 Elsevier B.V. All rights reserved.