TiO_2 and MgO doped ZnO conductive ceramics

Al2O3,TiO2 and MgO doped ZnO-based conductive ceramics were prepared.The effects of TiO2,MgO additive contents on the relative density,resistivity,temperature coefficient of ZnO conductive ceramics were investigated.U-I characteristic of ZnO conductive ceramics under low current and pulse current were analysed.The results show that Ti additive promotes sintering,when TiO2 content is 0.6wt%,relative density and resistivity under room temperature and low current is 96%,8.14Ω·cm respectively.Resistivity decreases when doped moderate amount of MgO:when MgO content is 0.4wt%,the minimum resistivity is 5.67Ω·cm.Resistance temperature coefficient can be improved with moderate amount of MgO.The obtained ZnO conductive ceramics have linear U-I characteristic under low current,but show nonlinearity under surge current.