一种新型NTC厚膜电阻的制备及电性能研究

以新型BaCoⅡ 0.05CoⅢ0.1Bi0.85O3材料为基体,以CuO为烧结助剂,在790、800、810℃烧结4h制备了NTC厚膜电阻。借助XRD、SEM和阻温特性测试仪,研究了CuO含量对电阻相组成、微观结构及电性能的影响。结果表明:烧结温度为800℃的NTC厚膜电阻主要物相为具有复合立方钙钛矿结构的BaCoⅡ0.05CoⅢ0.1Bi0.85O3,并有少量Bi2O3剩余;该组电阻表面颗粒均匀细小,致密性随CuO含量的增加而趋于增加。对烧结温度为790℃的电阻来说,其室温电阻R25和B25/85随CuO含量的增加而逐渐降低;该电阻的R25、B25/85及活化能Ea分别为0.98~13.40kΩ、931~1855K和0.08~0.16eV。

Preparation and electrical properties of a new kind of NTC Thick-film thermistor

NTC thick-film thermistros were prepared after sintering at 790、800、810 ℃ for 4 h, with new BaCo_(0.05)~ⅡCo_(0.1)~ ⅢBi_(0.85)O_3 material as the substrate and CuO as the sintering aids.The effects of CuO content on the phase composition, microstructure and electrical properties of thermistors were studied by XRD, SEM and resistance-temperature detector.The results show that the major phase of thermistors sintered at 800 ℃ is BaCo_(0.05)~ⅡCo_(0.1)~ ⅢBi_(0.85)O_3 with a cubic double perovskite structure, and there is a small amount of Bi_2O_3 remained in these thermistors containing fine uniform grains; The amount of pores present in these thermistors decreases with increasing CuO content, while the compactness increases.The room temperature resistance R_(25) and the B_(25/85) of thermistors sintered at 790℃ decreases with increasing CuO content; And, the R_(25), B_(25/85) and activation energy E_a of these thermistors are in ranges of 0.98～13.4 kΩ、931～1 855 K and 0.08～0.16 eV, respectively.