Dielectric relaxations of LaAlO3 ceramics over broad temperature range
Dielectric relaxations of LaAlO3 ceramics over broad temperature range
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DOI：
10.1016/j.jallcom.2012.12.041
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发表时间：
2013-04
影响因子：
6.2
通讯作者：
C. Lei;Chunchang Wang;Guojing Wang;Xiaohong Sun;Teng Li;Lina Liu
中科院分区：
文献类型：
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作者：
C. Lei;Chunchang Wang;Guojing Wang;Xiaohong Sun;Teng Li;Lina Liu
采用固相反应法制备了laalo3陶瓷。在100 ~ 1100K的宽温度范围内详细研究了材料的低频介电性能。我们发现，在500K以下，laalo3呈现出与频率和温度无关的平坦介电平台。当温度高于500K时，观察到两种热激活的介质弛豫，低温弛豫活化能为1.13eV，高温弛豫活化能为1.9eV。结果表明，低温弛豫与氧空位跳跃运动引起的体效应有关，高温弛豫与界面效应引起的麦克斯韦-瓦格纳弛豫有关。
LaAlO3ceramics were prepared via the solid-state reaction route. The low-frequency dielectric properties were investigated in detail in a broad temperature range from 100 to 1100K. We found that LaAlO3shows a flat dielectric plateau independent of frequency and temperature below 500K. When temperature higher than 500K, two thermally activated dielectric relaxations were observed with the activation energy of 1.13eV for the low-temperature relaxation and 1.9eV for the high-temperature relaxation. Our result indicates that the low-temperature relaxation is related to the bulk effect due to hopping motions of oxygen vacancies and the high-temperature relaxation was associated with the Maxwell–Wagner relaxation due to the interface effect.