In this study, phase-pure titanium dioxide TiO2 ceramics are sintered using standard high-temperature solid-state reaction technique at different temperatures (1,000, 1,100, 1,200, 1,300, 1,400 oC). The effect of sintering temperature on the densification and impedance properties of TiO2 ceramics is investigated. The bulk density and average grain size increase with the increase of sintering temperature. Impedance spectroscopy analysis (complex impedance Z * and complex modulus M *), performed in a broad frequency range from 100 Hz to 10 MHz, indicates that the TiO2 ceramics are dielectrically heterogeneous, consisting of grains and grain boundaries. The complex impedance Z *-plane indicates the resistance of grains of the TiO2 ceramics increases with increasing sintering temperature, while that of grain boundaries develops in the opposing direction. The complex modulus M *-plane shows a grain capacitance that seems to be independent of the sintering temperature, while that of the grain boundaries decreases with increasing sintering temperature. These results suggest that different sintering temperatures have effects on the microstructure, leading to changes in the impedance properties of TiO2 ceramics.

Abstract
1. Introduction
2. Experiment
3. Results and Discussion
4. Conclusion
References

• Liqi Cui, Ruifeng Niu(Institute of Opto-Electronic Information Science and Technology, Yantai University, Yantai 264005, P.R. China)
• Weitian Wang(Institute of Opto-Electronic Information Science and Technology, Yantai University, Yantai 264005, P.R. China) Corresponding author