High-permittivity core/shell stuctured NiO-based ceramics and their dielectric response mechanism
High-permittivity core/shell stuctured NiO-based ceramics and their dielectric response mechanism
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DOI：
10.1103/physrevb.72.014103
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发表时间：
2005-07-01
影响因子：
3.7
通讯作者：
Nan, CW
中科院分区：
文献类型：
--
作者：
Lin, YH;Jiang, L;Nan, CW
成功制备了高介电常数的核壳结构NiO基陶瓷（LSNO）。所有烧结的LSNO陶瓷样品都具有高的介电性能，LSNO-1样品的介电常数达到约1.2 × 10（4）。Si的浓度对LSNO陶瓷的介电性能有显着的影响，由于不同的激活能对应的介电弛豫过程。实验结果表明，极化弛豫与晶粒内部电导率关系密切，弛豫时间与温度的反向关系拟合的激活能E-g和电导率与温度的反向关系拟合的激活能E-a几乎相同。在这些LSNO陶瓷中观察到的高介电常数的起源归因于Maxwell-Wagner极化机制和热激活机制。用边界层模型计算的介电常数与实验结果符合得很好。
High-permittivity dielectric core/shell structured NiO-based ceramics (LSNO) have been successfully prepared. All the LSNO ceramic samples sintered exhibit high dielectric properties, and the dielectric constant reaches about 1.2x10(4) for the LSNO-1 sample. The concentration of Si has a remarkable effect on the dielectric properties of the LSNO ceramics due to the various activation energies corresponding to the dielectric relaxation processes. The experimental results indicate that the polarization relaxation has a close relation with the conductivity in grain interior because the activation energy values, E-g fitted by the reverse temperature dependence of the relaxation time and E-a fitted by the reverse temperature dependence of the dc conductivity, are almost same. The origin of the high permittivity observed in these LSNO ceramics is attributed to the Maxwell-Wagner polarization mechanism and thermally activated mechanism. The calculated dielectric constants by the boundary layer model are in good agreement with the experimental results.