Impedance spectroscopy and conduction mechanism of magnetoelectric hexaferrite BaFe10.2 Sc1.8 O19
Impedance spectroscopy and conduction mechanism of magnetoelectric hexaferrite BaFe10.2 Sc1.8 O19
复制标题
磁电六方铁氧体BaFe10.2 Sc1.8 O19的阻抗谱及传导机理
DOI：
10.1111/jace.16275
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发表时间：
2019
影响因子：
3.9
通讯作者：
Hao Yang
中科院分区：
文献类型：
--
作者：
Qishan Zhu;Rujun Tang;Hao Zhou;Yu Wang;Sicheng Xu;Jianmin Zhang;Changjun Jiang;Xiaodong Su;Hao Yang
采用阻抗谱（1 Hz-2 GHz）研究了不同温度（253 - 473 K）下六角铁氧体BaFe10.2Sc1.8O19（BFSO）陶瓷的介电弛豫和导电性能。BFSO的阻抗谱和模量谱的频率依赖性表明其介电响应是热激活的。阻抗谱的标度行为表明，BFSO的介电弛豫时间分布与温度无关。频率依赖的电导率谱在高温下遵循普适幂律，但在低温下略有偏离。在阻抗谱和电导率谱中也观察到BFSO在413 K以上的弛豫/导电激活能的巨大增加。这表明在高温下，弛豫/导电过程可能主要由可移动的氧空位贡献，而在低温下，电子跳跃占主导地位。电导率拟合结果进一步表明，电子/氧空位相关的小极化子跳跃应该是BFSO最可能的导电机制。
The dielectric relaxation and conduction properties of hexaferrite BaFe10.2Sc1.8O19(BFSO) ceramics have been investigated by impedance spectroscopy (1 Hz‐2 GHz) at various temperatures (253‐473 K). The frequency dependence of impedance and modulus spectra of BFSO shows that its dielectric responses are thermally activated. The scaling behaviors of impedance spectra indicate that the distribution of dielectric relaxation times in BFSO is temperature independent. The frequency‐dependent conductivity spectra follow the universal‐power‐law at high temperatures but deviate slightly at low temperatures. An enormous increase in relaxation/conduction activation energies of BFSO above 413 K is also observed in both impedance and conductivity spectra. This indicates that at high temperatures, relaxation/conduction processes may be contributed mainly by the movable oxygen vacancies, whereas at low‐temperature electron hopping dominates. The conductivity fitting results further suggest that electron/oxygen vacancy‐related small polaron hopping should be the most probable conduction mechanism for BFSO.