BaBiO_3掺杂BaFe_(0.4)Sn_(0.6)O_3负温度系数热敏电阻的电学性能(英文)

Electrical Properties of BaBiO_3-Doped BaFe_(0.4)Sn_(0.6)O_3 Negative Temperature Coefficient Thermistors

用传统固态反应法制备多晶(1-x)BaFe0.4Sn0.6O3-xBaBiO3(0.05<x≤0.2)热敏陶瓷。用X射线衍射分析仪、带有能谱仪的扫描电子显微镜及阻温测试仪研究热敏陶瓷的渗流阀值、微结构和电学性能。结果发现:烧结(1-x)BaFe0.4Sn0.6O3-xBaBiO3陶瓷由钙钛矿型单斜BaBiO3和立方BaFe0.4Sn0.6O3组成;BaBiO3含量越多,热敏陶瓷的颗粒尺寸就越大;基于不同的BaBiO3含量,(1-x)BaFe0.4Sn0.6O3-xBaBiO3负温度系数热敏陶瓷表现出不同的电学性能;随着BaBiO3含量的增加,热敏陶瓷的室温电阻率、热敏常数及活化能均降低,分别为0.1～183.8 k?.cm、2 832～5 516 K及0.25～0.48 eV,渗流阀值为x=0.12时的BaBiO3含量。

Polycrystalline（1-x）BaFe0.4Sn0.6O3-xBaBiO3（0.05x≤0.2） thermistor ceramics were prepared using a solid-state reaction method.Percolation threshold,microstructures and electrical properties of the thermistors were investigated using an X-ray diffrac-tometer,a scanning electron microscopy equipped with an energy-dispersive X-ray analyzer,and a resistance-temperature detector.The as-sintered（1-x）BaFe0.4Sn0.6O3-xBaBiO3 ceramics were composed of a monoclinic perovskite phase isomorphic to BaBiO3 and BaFe0.4Sn0.6O3 phase with a cubic perovskite structure.Results show that the greater the amount of BaBiO3 in the（1-x）BaFe0.4Sn0.6O3-xBaBiO3 samples,the more large particles there are in the thermistor ceramics.The BaBiO3-doped BaFe0.4Sn0.6O3 negative temperature coefficient thermistors provide various electrical properties,depending on BaBiO3 content.Electrical resistivity at 25 ℃ ρ25,thermistor constant B25/85 and activation energy Ea of the thermistors decrease with increasing the BaBiO3 content,which are in the range of 0.1-183.8 k.cm,2 832-5 516 K and 0.25-0.48 eV,respectively.The percolation threshold is a composition with a BaBiO3 content of x=0.12.