The influence of ZrO2 doping on microstructure and electrical properties of ZnO-based conductive ceramics.

ZnO-based conductive ceramic materials doping ZrO 2 were prepared at 1320 °C by the conventional solid-state sintering method in air, and the influence of comprehensive properties with different ZrO 2 -doped content were studied carefully. Microstructure and crystals of the samples were investigated by SEM and XRD respectively. As a donor, Zr4+ increases the carrier concentration and decreases the resistivity of grain and grain boundary. As-prepared samples shown excellent linear V–I characteristics and were suitable for high frequency electric field. With the increasing of dopant ZrO 2 contents, the dielectric constant and resistivity of ZnO-based conductive ceramics were influenced significantly, moreover, the resistance-temperature characteristics presents the negative temperature coefficient effects. ZnO-based conductive ceramics exhibited excellent comprehensive electrical performance with 0.30 mol% ZrO 2 -doping, in which the nonlinear coefficient is 1.01, the grain boundary barrier height is 0.014 eV, and the resistance temperature coefficient is −2.6×10−3/°C. [ABSTRACT FROM AUTHOR]