极化子
极化率
介电常数
载流子
凝聚态物理
电介质
材料科学
电荷(物理)
高原(数学)
电阻率和电导率
大气温度范围
物理
热力学
光电子学
量子力学
数学
电子
数学分析
分子
作者
Laijun Liu,Shaokai Ren,J. Liu,Fusheng Han,J. Zhang,Biaolin Peng,Dawei Wang,Alexei A. Bokov,Zuo‐Guang Ye
出处
期刊:Physical review
日期:2019-03-25
卷期号:99 (9)
被引量:67
标识
DOI:10.1103/physrevb.99.094110
摘要
${\mathrm{CaCu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$ (CCTO) has a large dielectric permittivity plateau near room temperature due to several dynamic processes. Here, we consider the combined effects of localized charge carriers (polarons) and conductive charge carriers using a recently proposed statistical model [Phys. Rev. B 96, 054115 (2017)] to fit and understand its permittivity measured at different frequencies over a broad temperature range. We found that, at the lowest temperature, the small permittivity is related to frozen polarons, and the increase at higher temperatures is associated with the thermal excitation of polarons that gives rise to the Maxwell-Wagner effect. The final rapid increase at the highest temperature is attributed to thermally activated conductivity. Such an analysis enables us to separate the contributions from localized polarons and conductive charge carriers and quantify their activation energies, which also explains the permittivity plateau near room temperature. In particular, we show that the subtle balance between the number of activated polarons and their polarizability causes CCTO to have a permittivity plateau with small dielectric loss.
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