BaBi2Nb2O9掺杂对BaTiO3基PTCR材料组织和性能的影响

Effect of dopant BaBieNb2O9 on microstructure and electronic properties of BaTiO3-based PTCR ceramics

研究了BaBi2Nb2O9掺杂对BaTiO3基PTCR材料的组成和断面形貌以及材料中BaBi2Nb2O9的含量和烧结工艺对材料电性能的影响。结果表明经过BaBi2Nb2O9掺杂对BaTi03基材料具有典型的PTC效应。并且随着材料中BaBi2Nb2O9掺杂量的增加，材料的室温电阻率减小到一个最小值然后又开始增大。利用扫描电镜分析了样品的断面形貌，随着BaBi2Nb2O9掺杂量的增加，样品的平均晶粒尺寸减小。在BaBi2Nb2O9掺杂量一定的情况下，研究了烧结温度对材料电性能的影响规律。当烧结温度为1290℃时材料可以得到最小的室温电阻率。

The components and cross sectional morphologies and the effect of BaBi2Nb2O9 content and sintering procedure on electrical properties of BaTiO3-based positive temperature coefficient resistivity （PTCR） materials were all investigated. The results show that all the prepared BaBi2Nb2O9 doping BaTiO3-based thermistors show typical PTC effect. As the amount of BaBi2Nb2O9 added in BaTiO3-based ceramics increases, the room temperature resistivity decreased to a minimum and then increased again. SEM was employed to investigate the microstructure in the samples. With an increase in BaBi2Nb2O9 content the mean grain size decreases. At a given content of BaBi2Nb2Og, the influence of sintering temperature on the electrical properties of samples has been investigated. A minimum of room temperature resistivity is obtained at the sintering temperature equal to 1290℃.