影响BaTiO_3基PTC陶瓷材料性能因素的分析

FACTORS ANALYSIS OF AFFECTING BaTiO_3-BASED PTC CERAMIC PROPERTIES

在BaTiO3基质中用15mol%Pb作移峰剂,以此为基础配料制备了Bi和V分别取代部分Pb的PTC陶瓷及BaTiO3-钛酸钡钠(NBT)陶瓷,采用SEM、EDS等方法对其性能进行了测试,并分析研究了烧成制度对显微结构的影响以及晶界重氧化对材料电性能和PTC效应的影响.结果表明:Bi3+取代微量Pb2+可以使BaTiO3半导化,且具有PTC效应,但是室温下其电阻较大;用V5+取代微量Pb2+,不能实现BaTiO3的半导化;NBT-BaTiO3陶瓷在还原气氛下烧结,半导化效果良好,但没有PTC效应,经重氧化试样的室温电阻增加,具有PTC效应.

PTC ceramics were prepared by Bi, V replace the lead which was contained 15mol% gradually, and BaTiO3-NBT. The effect of sintering on PTC ceramics the microstructure were studied, and the effect of reoxidation on the effect of PTC by XRD,SEM,EDS etc. The results are found that PTC ceramics have the effect of PTC after Bi doping, but the electrical resistance are larger. The ceramics have not good semi-conduction after Bi doping. NBT-BaTiO3 have good semi-conduction when sintered in the reducing atmosphere, but do not have the effect of PTC, the ceramics have the effect of PTC after reoxidation, but the electrical resistance increased.