Abstract: The effects of Co2O3/Co3O4-doped amount on the phase structure, microstructure and electrical properties of BaCoⅢxBi1-xO3 (x=0.02,0.04,0.06,0.08) and BaCoⅡx/3CoⅢ2x/3Bi1-xO3 (x=0.02,0.04,0.06,0.08) based thermistor ceramics were investigated by X-ray diffraction, scanning electron microscope and ρ-t characteristic tester.The results show that the matrix phase is a continuous solid solution with pervoskite structure.The content of Co2O3/ Co3O4 has dramatically impact on the electrical properties.With the increase of the Co2O3/ Co3O4-doped amount, both ρ25 and B25~85values of the ceramic sample reduce initially and then increased.The BaCoⅢ0.06Bi0.94O3 ceramics show excellent NTC properties of ρ25=12.19 Ω·cm, B25~85=717 K.A good NTC properties of ρ25=12.32 Ω·cm and B25~85=1069 K was also obtained for BaCoⅡ0.02CoⅢ0.04Bi0.94O3.

Key words: BaBiO3;thermistor ceramic;NTC;resistivity