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金属PTC陶瓷复合材料结构及其导电机理 被引量:4

Structure and Conductive Mechanism of Metal PTC Ceramic Composite
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摘要 研究了金属PTC陶瓷复合材料的电学性能和其材料组分。结果表明,掺入金属的PTC陶瓷材料经氮气中烧结,然后在空气中进行热处理,材料表面形成高势垒层,金属PTC陶瓷复合材料的室温电阻较PTC的陶瓷高。样品之中存在大量不同类型的极化,在低温时样品电阻较高,温度增加后,大量各种类型离子极化出现,在变价金属铁的变价导电作用下,削弱表面势垒,使金属PTC陶瓷复合材料电阻降低,表现出NTC现象。在电场作用下,正负电荷、晶粒畸变和空位缺陷等产生空间电荷极化使金属PTC陶瓷复合材料有较高介电常数。介电损耗(tgδ)频谱和介电δ温度谱上都出现一个介电峰,其主要原因是跃迁极化,金属阳离子由一个位置跃迁到另一个位置。 The composition and conductive mechanism of the metal PTC ceramic composite were investigated.It is shown that the PTC ceramic material doped with metal is sintered in the reducing atmosphere N 2, after thermal treatment in air, there are high build in potential layers on the material surface. The room temperature resistance of the metal PTC ceramic composite is higher than that of PTC semiconductor. A great variety of polarizations are there in the metal PTC ceramic composite. At low temperature, the resistance of the metal PTC ceramic composite is higher,and at high temperature, a variety of polarizations to start working,including the charges of Fe chemical valence cause the decrease in surface build in potential,and the samples exhibited NTC phenomenon. The samples have much higher dielectric constants, that is because the space polarizations of the positive and negative charges, crystal lattices and vacance defects. There are maxima in dielectric constant temperature and dielectric loss frequency of the samples, which are caused by the transition of the positive ions. The temperature and frequency maxima corresponding to the dielectric loss peak are consistent with the maxima of positive ion mobility.
出处 《压电与声光》 CAS CSCD 北大核心 1997年第3期196-200,共5页 Piezoelectrics & Acoustooptics
基金 云南省教委科研基金
关键词 PTC NTC 陶瓷复合材料 结构 PTC,NTC,ceramic compostie, thermal treatment, depletion layer
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参考文献5

  • 1张端明,华中理工大学学报,1995年,23卷,10期,122页
  • 2张端明,无机材料学报,1995年,10卷,2期,245页
  • 3王义华,硕士学位论文,1993年
  • 4Wang D Y,J Am Ceram Soc,1990年,73卷,6期,1574页
  • 5Wang D Y,J Am Ceram Soc,1990年,73卷,3期,669页

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