Structural, microstructure and electric properties of SnO2-Sb2O5-Cr2O3 varistor ceramics doped with Co2SnO4 spinet phase previously synthesized

The present investigation reports the variations of the microstructure, structure and electrical properties due to a change in the Co2SnO4 content of SnO2-Cr2O3-Sb2O5 ceramic samples. The ceramic system was (99.9-X) % SnO2- X% Co2SnO4- 0.05%Sb2O5-0.05% Cr2O3, where X = 0, 0.5, 1, 2 and 4 mol %. In order to obtain a comprehensive knowledge of the samples, characterization techniques such as Thermal Analysis, X-ray Powder Diffraction (XRD) with Rietveld refinement, and Scanning Electron Microscopy where carried out. On the subject of the electrical properties of the studied system, the samples showed a tendency to decrease values of breakdown electric field (from 6219.30 to 1155.72 Vcm(-1)) as the spinet content increased. Authors suggest the ceramic system may found application as medium-voltage varistors. (C) 2017 Elsevier B.V. All rights reserved.