Effects of cobalt doping on the microstructure, complex impedance and activation energy in 0.2PZN–0.8PZT ceramics
Effects of cobalt doping on the microstructure, complex impedance and activation energy in 0.2PZN–0.8PZT ceramics
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DOI：
10.1016/j.matchemphys.2012.11.068
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发表时间：
2013-02
影响因子：
4.6
通讯作者：
Mupeng Zheng;Y. Hou;Jingyong Fu;Xinwei Fan;M. Zhu;Hui Yan
中科院分区：
文献类型：
--
作者：
Mupeng Zheng;Y. Hou;Jingyong Fu;Xinwei Fan;M. Zhu;Hui Yan
制备并研究了添加CoCO3的Pb((Zn1/3Nb2/3)0.20(Zr0.50Ti0.50)0.80)O3(0.2PZN–0.8PZT(+xCoCO3)体系。随着CoCO3含量的增加，样品的四方形变量c/a突然增大，但对于x=0.2PZN-0.8PZT%的≥，c/a几乎不变，证实了CoCO3在0.2PZN-0.8PZT中的溶解极限约为x0=0.2wt%。复阻抗谱分析在250-300℃的温度范围内，从1 MHz到10 MHz，提供了另一个证据，即0.2wt%确实是溶解度极限。在相似的频率范围内观察到Z“和M”随频率变化的谱峰，表明在所研究的体系中存在近似的德拜行为。发现随温度变化的体弛豫值服从线性Arrhenius拟合。结果表明，CoCO3掺杂0.2PZN-0.8PZT时，单、双离化氧空位对导电过程均有贡献。
A CoCO3added Pb((Zn1/3Nb2/3)0.20(Zr0.50Ti0.50)0.80)O3(0.2PZN–0.8PZT + xCoCO3) system has been prepared and investigated. The tetragonal distortion c/a of specimens increases abruptly with increasing CoCO3content, but is almost constant for x ≥ 0.2 wt%, confirming that the solubility limit of CoCO3in 0.2PZN–0.8PZT is about x = 0.2 wt%. Complex impedance spectroscopic analysis, in the temperature range of 250–300 °C from 1 mHz to 10 MHz, provides another evidence that 0.2 wt% is indeed the solubility limit. Both spectroscopic peaks of Z″ and M″ vs frequency are observed in the similar frequency region, indicating the approximated-Debye behavior in the studied systems. Temperature dependent bulk relaxation values are found to obey linear-Arrhenius fit. Based on the activation energy values, it can be concluded that in CoCO3doping 0.2PZN–0.8PZT, both the single and double ionized oxygen-vacancies contribute to the conduction process.