Eur. Phys. J. Plus (2016) 131: 444
https://doi.org/10.1140/epjp/i2016-16444-4

Regular Article

Study of the effect of substitution by MnO₂ and V₂O₅ on the microstructure, electrical and dielectric characteristics of zinc oxide ceramics

¹ Engineering Basic Sciences Department, Faculty of Engineering, Menoufia University, Shebin El-Kom, Egypt
² Bilbis Higher Institute of Engineering (BHIE), Bilbis, Sharqia, Egypt

^* e-mail: osama_amin2015@yahoo.com

Received: 23 December 2015
Accepted: 21 November 2016
Published online: 27 December 2016

Abstract

As a consequence of their established properties in varistors, V₂O₅ and MnO₂ dopants were added to ZnO ceramics to improve their microstructural, non-linear electrical as well as their dielectric properties. Samples of the general chemical formula (100-2x) ZnO-x V₂O₅-x MnO₂, mol%, were prepared using the conventional ceramic technique at five sintering temperatures, namely 800 ^°C, 900 ^°C, 1000 ^°C, 1100 ^°C and 1200 ^°C, for 2 hours. The maximum shrinkage and minimum water absorption percentages were recorded at the sintering temperature 1200 ^°C. This temperature was selected as the appropriate sintering temperature for all the samples. The structure of the prepared samples was examined using XRD and EDAX measurements. SEM micrographs revealed that the selected sintering temperature improved the microstructure of the samples and strongly affected the non-linear behavior of the prepared samples. The values of the non-linear coefficient () improved with the increase of V₂O₅ and MnO₂ mol%. Upon studying the frequency and compositional dependence of the dielectric constant () and ac conductivity (), a significant improvement in the dielectric properties was detected with increasing V₂O₅ and MnO₂ mol%.