【摘要】 采用丝网印刷工艺制备了CuO/BaCoⅡ0.02Co Ⅲ0.04Bi0.94O3共掺Ba0.5Bi0.5Fe0.9Sn0.1O3热敏厚膜,并借助X射线衍射仪、扫描电子显微镜及交流阻抗谱对厚膜的物相、形貌和电学性能进行表征分析。CuO的存在使得厚膜中的BaCoⅡ0.02Co Ⅲ0.04Bi0.94O3出现分解行为和非钙钛矿Ba-Bi氧化物的形成,厚膜主要由大量的颗粒链组成,单个颗粒链主要由Ba0.5Bi0.5Fe0.9Sn0.1O3构成的小晶粒和低熔点的BaCoⅡ0.02Co Ⅲ0.04Bi0.94O3大晶粒组成。当厚膜中CuO含量添加至10%时,可获得最低的室温电阻率;300 h 150℃下,CuO含量为4%的厚膜老化率约为2.3%。厚膜的电学性能主要来自于晶界的贡献,较低温区内晶界表现为氧空位电导,较高温区下为电子与氧空位耦合电导。更多还原

【Abstract】 CuO and BaCoIⅡ0.02CoⅢ0.04 Bi0.94O3 co-doped Ba0.5Bi0.5 Fe0.9Sn 0.1O3 thick films were fabricated by screen-printing technology.The phases,surface topologies and electrical properties of the thick films were characterized by X-ray diffraction,scanning electronic microscopy and AC impedance analyzer.The added CuO in thick films led to the decomposition of BaCoII 0.02CoⅢ0.04Bi0.94O3 compound and then the formation of non-perovskite bismuth barium oxides.A number of particle chains were observed in the thick-film thermistors and each particle in chains was composed of fine-grain Ba0.5Bi0.5Fe0.9Sn0.1O3 and coarse-grain BaCoⅡ0.02CoⅢ0.04Bi0.94O3 with low melting.A lowest value of room-temperature resistivity was obtained for the thick-film composition containing 10% CuO.The resistivity drift of 2.3% with duration time about 300 h at aging temperature 150 ℃ was observed for the film containing 4% CuO.The electrical properties of thick films were mainly attributed to the contribution of grain boundaries which showed the oxygen-vacancy conduction in low measured temperature range,and electron and oxygenvacancy coupling conduction in high measured temperature region.更多还原