The role of A-sited elements in double perovskite colossal dielectric LiCuNb₃O₉ has been analyzed by replacing the Cu ions with Li ions. Structural analysis revealed the presence of Jahn-Teller effect because of the Cu ions. Two thermally activated relaxations have been observed: the lower temperature one has been assigned to be a polaronic relaxation following Mott variable-range-hopping mechanism. Impedance analysis and humidity sensitive test proved that the higher temperature one is a Maxwell-Wagner relaxation. Our work highlights that the polaronic hopping is responsible for the colossal dielectric permittivity behavior of LiCuNb₃O₉.

中文翻译：

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LiCuNb ₃ O _9中Jahn-Teller辅助极化电子跳跃

通过用Li离子代替Cu离子，分析了A位元素在钙钛矿双电介质LiCuNb ₃ O ₉中的作用。结构分析表明，由于铜离子的存在，Jahn-Teller效应的存在。已经观察到两个热激活的弛豫：遵循莫特可变范围跳跃机制，较低的温度被指定为极化子弛豫。阻抗分析和湿度敏感测试证明，较高的温度是麦克斯韦-瓦格纳弛豫。我们的工作强调了极化子跳跃是LiCuNb ₃ O ₉的巨大介电常数行为的原因。