无机材料学报

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PTCR陶瓷中的电阻率反常现象

虞孝栋; 李国荣   

  1. 中国科学院上海硅酸盐研究所无机功能材料开放实验室;上海 200050
  • 收稿日期:1996-10-17 修回日期:1997-01-16 出版日期:1997-06-20 网络出版日期:1997-06-20

Abnormal Resistance Properties in PTCR Barium Titanate

YU Xiaodong; LI Guorong   

  1. Laboratory of Functional Inorganic Materials; Shanghai Institute of Ceramics; Chinese Academy ofSciences Shanghai 200050 China
  • Received:1996-10-17 Revised:1997-01-16 Published:1997-06-20 Online:1997-06-20

摘要: 本文叙述了在50kHz以上高频域内,发现钛酸例基PTCR陶瓷材料Ba0.93Sr0.03Ca0.04TiO3xmolY2O3+1wt%AST的高频电阻-温度特性曲线呈现负突变的反常现象.对于这一反常现象,本文用PTCR陶瓷的晶粒-晶界二层电介质模型分析了不同频率下的电学等效电路,从而解释了上述现象.利用上述等效电路,还解释了该材料在100Hz至5MHz的频率范围内有效介电系数温度谱随频率增加而出现峰分裂的现象,以及电容损耗温度谱随频率变化的原因.

关键词: PTCR陶瓷, 高频电阻, 反常现象

Abstract: In this paper the resistance properties of PTCR barium titanate [Ba0.93Sr0.03Ca0.04 TiO3xmolY2O3+1wt% AST] were measured near Curie-temperature by a complex impedance analyzer(HP4192A) from 10Hz to 10MHz. It was observed that PTCR sample exhibits an abnormal negative-temperature- coefficient in frequencies higher than 50kHz. This phenomenon can be simply explAlNed by the two dielectric-layer model, and with this model, the behavior of effectivedielectric constant and its loss in wide frequency range can be explained as well.

Key words: PTCR ceramics, high-frequency resistance, abnormal