Bi2O3对CaMnO3热电材料微观结构和高温电性能的影响研究

Effect of Bi2O3 on Microstructure and High-Temperature Electrical Properties of CaMnO3

以CaCO3, MnO2, Bi2O3为原料,采用传统的固相反应法制备CaMnO3前驱粉体。采用Bi2O3作为助熔剂与CaMnO3复合,研究Bi2O3用量对CaMnO3热电材料微观结构和高温电性能的影响。结果表明,Bi2O3可以有效地将CaMnO3的烧结温度降低到1200℃,制备出的CaMnO3-xBi2O3的热电材料为单一的物相,并且随着Bi2O3添加量的变大,CaMnO3的晶粒细化。随着Bi2O3加入量的增加,样品的室温及高温电阻率减小。当x=3时,室温电阻率最小为1.06×10^-4Ω·m,是CaMnO3的1/3。

In this paper, CaCO3, MnO2 and Bi2O3 were used as raw materials to prepare CaMnO3 precursor powder by traditional solid reaction method. Bi2O3 was used as sintering aid compositing with CaMnO3. The effect of Bi2O3 dosage on the microstructure and high-temperature electrical properties of CaMnO3 was studied. The results show that Bi2O3 can effectively reduce the sintering temperature of CaMnO3 to 1200 ℃. The sample of CaMnO3-xBi2O3 is single phase, and the grain of CaMnO3 is refined as the amount of Bi2O3 increases. As the amount of Bi2O3 added increases, the roomtemperature and high-temperature resistivity of the sample decrease. When x=3, the resistivity is 1.06×10-4 Ω·m at room temperature, which is 1/3 of CaMnO3.