摘要
通过调整Al_2O_3/SiO_2的摩尔比,在晶界中形成了对Fe_2O_3、MgO等杂质有较大固溶能力的莫来石微晶,降低了晶粒表面势垒,达到降低室温电阻率的目的.总结了高温淬火与室温电阻率及PTC效应之间的规律,确定了适于低阻PTC材料的烧成工艺,并研制出了室温电阻率ρ_(20℃)为12.1Ω·cm,R_(max)/R_(20℃)为2.3×10 ̄3的低阻样品.
Intergranular mullite microcrystals have been obtained through adjusting the mole ratio of Al_2O_3/SiO_2. It shows comparatively strong solubility to Fe_2O_3, MgO and other foreign substances. Therefore the borrier potential of crystallite can be lowered, and the desired effect of lowering specific resistance can be brought about. In addition, , the relationship between quench temperature and specific resistance and the positive temperature coefficient (PTC dffect at) room-temperature has been presented. As well a proper sintering technique for producing PTC material with low specific resistance has been confirmed and a sample product with low resistivity of 121 .1Ω·cm at room-temperature, with R_(max)/R_(20℃) of 2.3 × 10~3, has been developed.
出处
《北京工业大学学报》
CAS
CSCD
1994年第3期66-69,共4页
Journal of Beijing University of Technology
关键词
PTC
电阻率
表面势垒
热敏电阻
positive temperature coefficient(PTC), resistivity, surface-barrior potential