摘要
采用固相烧结工艺制备出了Ｓｒ０．４Ｐｂ０．６ＴｉＯ３半导体陶瓷元件，其阻温特性具有独特的ＮＴＣＲ和ＰＴＣＲ复合效应，陶瓷室温电阻率及居里点以下的ＮＴＣＲ效应随着烧结温度的升高而提高，适当过量ＰｂＯ则能降低陶瓷室温电阻率及其ＮＴＣＲ效应．利用ＸＲＤ、ＳＥＭ和ＥＤＳ分别对样品的相结构、形貌及成份分布等进行分析，结果显示晶界中的Ｓｒ，Ｔｉ含量相对较高，而Ｐｂ含量相对较低，材料的阻温特性明显受其影响．铅挥发造成的阳离子空位是该类半导体陶瓷在居里点下出现ＮＴＣＲ效应的主要原因之一，同时探讨了Ｙ３＋离子掺杂（Ｓｒ，Ｐｂ）ＴｉＯ３陶瓷的半导化机理和热敏特性．
A kind of V-shaped thermistor based on Sr0.4Pb0.6TiO3 materials was fabricated by solid state reaction methods. The samples exhibit novel NTCR effect below the Curie temperature (T-c) and typical PTCR effect above T-c, the room- temperature resistivities and the values of log(rho(25degreesC)/rho(min)) increase with elevating soaking temperature. The phase structure, microstructure and compositional distribution of samples were investigated by using XRD, SEM and EDS respectively. The results show that Sr, Ti concentrations near the grian boundaries are higher than that in the grains. It is estimated that the NTCR effects of (Sr,Pb)TiO3 ceramics are closely related to the Pb2+ ionic vacancies near the grain boundaries. The semiconductive mechanism of Y3+-doped (Sr,Pb)TiO3 ceramics was also discussed.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2002年第2期311-315,共5页
Journal of Inorganic Materials
