MnO_2掺杂量对BaCo_(0.05)Co_(0.1)Bi_(0.85)O_3厚膜NTCR电性能影响

以新型BaCo0.05Co0.1Bi0.85O3材料为基体,掺杂不同摩尔分数x(MnO2),在840℃下烧结4h制备了NTC厚膜电阻。借助XRD、SEM和直流阻温特性测试仪,研究x(MnO2)对电阻相组成、微结构及电性能的影响。结果表明:所得的NTC厚膜热敏电阻主要物相为具有钙钛矿结构的BaCo0.05Co0.1Bi0.85O3,且表面致密。当x(MnO2)超过5%时,有新相BaMnO3开始沿晶界析出,获得小尺寸晶粒;厚膜电阻的室温电阻率ρ25及B25/85值随x(MnO2)增加而升高;当x(MnO2)为10%时,ρ25从初始的13.5?·mm升高为810.0?·mm,B25/85值从600K升高到2049K。

Effects of MnO2-doped amount on the electrical properties of BaCo0.05Co0.1Bi0.85O3 thick film thermistors NAME

NTC thick film thermistros were prepared after sintering at 840 ℃ for 4 h, with new type BaCo0.05Co0.1Bi0.85O3 material as the matrix and MnO2 as dopant. The effects of MnO2 doped amount on their phase composition, microstructure and electrical properties were studied by XRD, SEM and DC resistance-temperature cheracteristic detector. The results show that the major phase of obtained NTC thick film thermistors is BaCo0.05Co0.1Bi0.85O3 with a perovskite structure, and their surface is very dense. When x(MnO2) is over 5%, new phase BaMnO3 separates out around the grain boundary to get smaller grain size. The room temperature resistivity ρ25 and B25/85 value of the thermistors increase with the increase of x(MnO2). When x(MnO2) is 10%, the ρ25 increases from initial 13.5 ?·mm to 810.0 ?·mm, and B25/85 value rises from 600 K to 2 049 K.