【作者】 骆颖； 刘心宇； 李旭琼； 罗彦琦；

【Author】 LUO Ying, LIU Xin-yu, LI Xu-qiong ,LUO Yan-qi (College of Materials Science and Engineering, Central south University, Changsha 410083, China; Research Center for Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China; Guilin Academy of Air Force, Guilin 541004, China)

【机构】 中南大学材料科学与工程学院； 桂林电子工业学院材料中心；

【摘要】 研究了BaBiO3掺杂的BaTiO3基材料的组成、相结构和断面形貌以及材料中的BaBiO3的含量和烧结温度对材料的显微组织和电性能的影响。结果表明试验样品在比较宽的温度范围都显示良好的NTC 效应。X射线衍射分析表明烧结体中的相由立方结构的BaTiO3和单斜结构的BaBiO3组成。利用扫描电镜分析了样品的断面形貌,样品的平均晶粒尺寸随着材料中BaBiO3含量的增加而增大,同时粗晶粒和细晶粒的尺寸差也越来越大。样品的室温电阻率和B 25／125常数随着材料中的BaBiO3的含量的增加而增大。在给定的组分下,改变烧结温度,样品的室温电阻率和 B25/125常数随烧结温度的升高而增大。更多还原

【Abstract】 The components, phase structure and cross sectional morphologies, and the effects of BaBiO3 content and sintering temperature on microstructure and electrical properties of BaBiO3 doping BaTiO3-based NTC thermistors were all investigated. The results show that BaTiO3 materials doped with BaBiO3 only show negative temperature coefficient effect over a wide temperature range. X-ray diffraction analysis displays that Major phases present in the sintered bodies were the BaTiO3 compounds with a perovskite structure and the BaBiO3 compounds with a monoclinal structure. SEM was employed to investigate the microstructure of samples. The average grain size of the samples increased with increasing BaBiO3 contents. The distinction in size between large grains and fine grains became bigger and bigger with increasing BaBiO3 contents. The values of ρ 25 and B 25-125 constants of thermistors decreased with an increase in BaBiO3 content. Also, at a given composition, the resistivity and coefficient of temperature sensitivity for thermistors increased with an increase in sintering temperature.更多还原