Electrical properties of hexagonal BaTi0.8Co0.2O3−δ ceramic with NTC effect
Electrical properties of hexagonal BaTi0.8Co0.2O3−δ ceramic with NTC effect
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DOI：
10.1088/0022-3727/42/23/235103
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发表时间：
2009-12
期刊：
影响因子：
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通讯作者：
Jian Wang;Hong Zhang;Dan Xue;Zhicheng Li
中科院分区：
文献类型：
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作者：
Jian Wang;Hong Zhang;Dan Xue;Zhicheng Li
研究了以聚乙烯醇（PVA）为原料，采用湿化学法制备的BaTi0.8Co0.2O3-δ陶瓷的结构和电学性能。BaTi0.8Co0.2O3−δ的晶体结构被确定为六方相。电阻率温度特性的测量表明，该陶瓷具有负温度系数（NTC）的特性。阻抗谱和电模量谱分析表明，与晶界相比，晶粒对电性能起主要作用。观察到阻抗和电模量峰的归一化虚部的频率依赖图之间的重叠和分离的共存。提出了BaTi0.8Co0.2O3−δ热敏电阻NTC效应的跳跃模型和带导相结合的导电机制。
The structure and electrical properties of BaTi0.8Co0.2O3−δ ceramic prepared by a wet chemical process polymerized with polyvinyl alcohol were investigated. The crystal structure of BaTi0.8Co0.2O3−δ was determined to be a hexagonal phase. The measurements of temperature dependence of resistivity revealed that the ceramic has the characteristic of negative temperature coefficient (NTC) of resistivity. The electrical properties analysed by impedance and electrical modulus spectroscopies showed that the grains play a major role in electrical properties, compared with the grain boundaries. The co-existence of the overlapping and separation between the frequency dependence plots of the normalized imaginary part of impedance and electric modulus peaks is observed. The conduction mechanisms combining the hopping model and band conduction are proposed for the NTC effect in the BaTi0.8Co0.2O3−δ thermistor.