细晶粒BaTiO_3陶瓷电阻率和漏电流的尺寸效应研究

Study on the Size Effect of Resistivity and Leakage Current of Fine Grained BaTiO_3 Ceramics

BaTiO_3陶瓷材料作为一种重要的介电材料被广泛应用于诸多领域,其尺寸效应也被广泛的研究。试验发现不同频率下BaTiO_3陶瓷材料的电阻率的随晶粒尺寸变化而变化,由此提出一个BaTiO_3陶瓷等效电路模型,从理论上验证不同频率下影响电阻率的主导贡献因素。同时试验中发现直流与瞬态测试下的电阻率的尺寸效应变化相差较大,理论分析是由漏电流中极化电流与电导电流造成的。结果表明,瞬态测量与直流测量的差异确实由漏电流的尺寸效应引起的。

BaTi03 ceramic material is widely used in many fields as a kind of very important dielectric material, and the size effect has also been widely studied. This paper found that size effect of resistivity for BaTiO3 ceramics was changed with the change of grain size at different frequencies, and presented a equivalent circuit model of BaTiO3 ceramics, to verify the dominant factors that influence the resistivity under the different frequencies. The test results show that the size effect of resistivity have a great difference in the DC and transient test, and theoretical analysis believe it＇s caused by the polarization current and the conduction current in the leakage current. The results show that the difference between the transient and the DC measurement is caused by the size effect of the leakage current.