Structure and dielectric relaxation of double-perovskite La2CuTiO6 ceramics
Structure and dielectric relaxation of double-perovskite La2CuTiO6 ceramics
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DOI：
10.1063/1.3446846
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发表时间：
2010-06
影响因子：
3.2
通讯作者：
W. Yang;M. Mao;X. Liu;Xuying Chen
中科院分区：
文献类型：
--
作者：
W. Yang;M. Mao;X. Liu;Xuying Chen
研究了La2CuTiO6陶瓷在宽频率和宽温度范围内的介电性能。La2CuTiO6陶瓷介电性能的温度依赖性曲线中只有一个介电弛豫。这种介电弛豫是一个热激活过程。根据阻抗谱的最小均方拟合结果，可以得到体电阻和晶界电阻。目前陶瓷的传导机制也是一个热活化过程。介质弛豫的活化能与电导率的活化能几乎相同，这表明介质弛豫与电导率之间存在着密切的关系。该陶瓷的介电弛豫应归因于氧空位诱导的混合价结构（Cu+/Cu2+和Ti3+/Ti4+）。
Dielectric properties of La2CuTiO6 ceramics were investigated in a broad frequency and temperature range. There is only one dielectric relaxation in the curve of temperature dependence of dielectric properties for La2CuTiO6 ceramics. This dielectric relaxation is a thermal activated process. The bulk and grain boundary resistances can be obtained from results of the least-mean-square fitting on impedance spectra. The conduction mechanism of the present ceramics is also a thermal activated process. The activation energy of dielectric relaxation is almost same as that of electrical conductivity and this indicates the closely correlation between the dielectric relaxation and electrical conductivity. The dielectric relaxation in the present ceramics should be attributed to the mixed-valent structure (Cu+/Cu2+ and Ti3+/Ti4+), which is induced from the oxygen vacancy.