【摘要】 在（Ba—Pb）TiO₃固溶体系统中采用混合氧化物工艺制备了铁电相变温度为300℃的 PTCR 材料,其性能为:室温电阻率10⁴Ω·cm;电阻率在300℃附近突变10³;体积密度6.45g/cm³（～94%）。通过对样品的扫描电镜观察,研究了在该系统中材料的化学组成（添加物）、微观结构和宏观电性能之间的一些关系。过量 BaO、Al₂O₃和 SiO₂是本系统的有用添加物,因为它们能使材料的微观结构比较精细;Mn²⁺起了受主杂质的作用,它能增加材料的电阻率和电阻率～温度曲线的斜率,但是有时它会促进晶粒生长;过量 TiO₂在本系统中并不适宜,因为会产生粗晶的微观结构。本实验结果清楚地表明,样品的 PTCR 性能与它们的微观结构密切相关。更多还原

【Abstract】 PTCR material based on（Ba-Pb）TiO₃ solid solution was prepared by a mixedoxide method.The microstructure of the samples was observed and the followingproperties were obtained.Phase transition temperature——300℃,Resistivity at room temperature——10⁴Ω.cmJump in near 300℃——10³,Density（g/cm³）——6.45（～94%）Some relations between the additives,microstructures and electrioal properties havebeen obtained.Excess BaO,Al₂O₃ and SiO₂ are considered as the useful additives,because of their refining effects on the microstructure development.Mn²⁺ ion acts as anacceptor and increases the resistivity and the slope of ρ_v-T curve.However,it couldpromote the grain growth sometimes.Excess TiO₂ is not necessary,because of itsproducing coarse grain microstructure.The experimental results have shown that thePTCR behavior of the samples is closely related to their microstructures.更多还原