Colossal Permittivity and Variable-Range-Hopping Conduction of Polarons in Ni0.5Zn0.5Fe2O4 Ceramic
Colossal Permittivity and Variable-Range-Hopping Conduction of Polarons in Ni0.5Zn0.5Fe2O4 Ceramic
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Ni0.5Zn0.5Fe2O4 陶瓷中极化子的大介电常数和可变范围跳变传导
DOI：
10.1021/jp402320b
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发表时间：
2013-06
影响因子：
3.7
通讯作者：
Du, Piyi
中科院分区：
文献类型：
--
作者：
Zheng, Hui;Weng, Wenjian;Han, Gaorong;Du, Piyi
铁氧体的电性能对其在高频下的应用至关重要。本文研究了由柠檬酸燃烧法合成的粉末制备的Ni_（0.5）Zn_（0.5）Fe_2O_4陶瓷的庞介电常数行为。其体电导率归因于局域极化子的变程跳跃。这些极化子表现出普遍的介电响应与频率。它们在低温下被冻结，在高温下被激活。随着温度从235 K降低到130 K，它们的跳跃能从223 meV降低到113 meV，而估计的跳跃范围从3.5 nm增加到4.1 nm。基于内势垒层模型的修正Koops等效电路明确地建立了NZFO的极化子电导与巨介电常数之间的直接关系，并与实验数据进行了验证。
The electrical properties of ferrites are important to their applications at high frequencies. In this paper, we investigate the colossal permittivity behavior of Ni0.5Zn0.5Fe2O4 ceramic prepared from powders synthesized by the citric acid combustion method. Its bulk conductivity is attributed to the variable-range hopping of localized polarons. These polarons exhibit universal dielectric response with frequency. They are frozen at low temperature and activated at high temperature. As temperature decreases from 235 to 130 K, their hopping energy decreases from 223 to 113 meV, while the estimated hopping range increases from 3.5 to 4.1 nm. The direct correlation of polaron conduction and colossal permittivity of NZFO is definitely established by a modified Koops’ equivalent circuit based on the internal barrier layer model, which is well confirmed by the experimental data.
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DOI：
10.1088/0953-8984/23/49/495902
发表时间：
2011-12
期刊：
Journal of Physics: Condensed Matter
影响因子：
--
作者：
A. Karmakar;S. Majumdar;S. Giri
通讯作者：
A. Karmakar;S. Majumdar;S. Giri
影响因子：
1.6
作者：
F. Pizzitutti;F. Bruni
通讯作者：
F. Pizzitutti;F. Bruni
影响因子：
1.5
作者：
R. Satyanarayana;S. Murthy
通讯作者：
R. Satyanarayana;S. Murthy
影响因子：
2.7
作者：
K. Bharathi;C. Ramana
通讯作者：
K. Bharathi;C. Ramana
影响因子：
4
作者：
A. Dhar;Nidhi Singh;R. Singh;Ramadhar Singh
通讯作者：
A. Dhar;Nidhi Singh;R. Singh;Ramadhar Singh