Effect of V2O5 addition on the structural and electrical properties of CoTio3

Abstract The present work shows the electric and dielectric study of ceramic composites made from cobalt titanate CoTiO3 (CoTO) and vanadium oxide (V2O5), by complex impedance spectroscopy. The CoTO was obtained by solid state reaction, the structural properties of the CoTO and the composites were discussed using X-ray diffraction and the electric and dielectric study to possible applications in radio frequency was made by measurements analysis of impedance spectroscopy at room temperature and with temperature variation. The analysis of the diffractogram of the CoTO synthesis showed the formation of only a single phase of CoTO without presence of spurious phases and analysis of the diffractograms of the composites after sintering process revealed the formation of a secondary phase [Co3V2O8]. The CoTO study showed the electrical and dielectric properties of impedance (Z′), dielectric permittivity (e′), conductivity (σ) and activation energy (Ea), where they were studied in the frequency range from 1 Hz to 1 MHz and temperature (280–440 °C). The results indicate that CoTO electroceramics and ceramic composites presented a thermo-activated charge transfer process in the studied temperature range and the electrical results were modeled through equivalent circuit configurations composed of two and three associations in parallel with R-CPE, representing the electric responses of the grain, grain boundary and electrode effect presented by the studied electroceramics.