Zn掺杂对Ni-Mn-Cu-O系NTC热敏电阻的影响

Effects of Zn-doping on Ni-Mn-Cu-O system NTC thermistor

采用传统固相反应法制备了Zn掺杂的Ni0.5Mn2.38–x Cu0.12Znx O4(x=0,0.2,0.4,0.6,0.8)系列MF58型NTC热敏电阻工业化产品,使用XRD、SEM、XPS等技术手段表征了所制陶瓷烧结体的晶体结构、微观结构和成分,重点考察了Zn元素含量对热敏电阻电学性能和老化值的影响。结果表明:随着Zn含量的增加,Ni0.5Mn2.38–x Cu0.12Znx O4固溶体的晶体结构从立方尖晶石转变成四方尖晶石,样品的电阻率和热敏常数B值呈现逐步增加的趋势,同时老化值显著减小,当x=0.8时,其在150℃放置6天后的老化值可低至0.33%。

A batch of MF58 type thermistors with the composition of Ni0.5Mn2.38–x Cu0.12 Znx O4（x=0, 0.2, 0.4, 0.6, 0.8）were prepared using the conventional solid state reaction method. The phase structures, microstructures and compositions of the prepared ceramics were investigated with the help of XRD, SEM and XPS characterization techniques; meanwhile, the effects of Zn content on the electrical properties and aging values of those thermistors were specially studied. The results show that with the increase of Zn content, the crystal structure of those solid solutions transforms from cubic spinel into tetragonal spinel; the resistivity and B constant of the thermistors increase gradually, and the aging value decreases sharply.After stored at 150 ℃ for 6 days, the aging value is as low as 0.33% for the Ni0.5Mn1.58Cu0.12Zn0.8O4 thermistor.