Dielectric Relaxation Mechanism in NaNO 2
Dielectric Relaxation Mechanism in NaNO 2
复制标题
NaNO 2 中的介电弛豫机制
DOI：
10.1143/jpsj.24.1053
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发表时间：
1966
影响因子：
1.7
通讯作者：
I. Hatta
中科院分区：
文献类型：
--
作者：
Y. Yamada;Y. Fujii;I. Hatta
根据Ising系统随时间变化的统计特性，分析了NaNO 2中的介电弛豫，其中Ising变量对应于每个分子单元所携带的极化的两个稳定取向.采用无规相位近似，根据两个稳定取向之间的势垒Δ U计算了动态极化率，并将Δ U取为7.4kTN，较好地解释了反铁电转变温度TN以上复介电常数随温度和频率的变化.在分子间的相关性可忽略的高温下，每个NO2-离子的翻转运动的弛豫时间为10 - 11秒量级。在相变温度附近观察到的慢弛豫被解释为由于偏振相关涨落的物理减慢过程。从长程性质的角度讨论了单色散特性。
The dielectric relaxation in NaNO 2 is analyzed on the basis of the time dependent statistics of the Ising system, where the Ising variable corresponds to two stable orientations of the polarization carried by each molecular unit. The dynamical susceptibility is calculated with the random phase approximation in terms of the potential barrier Δ U between two stable orientations, The observed temperature and frequency dependences of the complex dielectric constants above the antiferroelectric transition temperature T N are explained reasonably well by taking Δ U as \(\varDelta U{\cong}7.4kT_{N}\). The relaxation time of the flipping motion of each NO 2 - ion at high temperatures where the correlation between molecules is negligible is of the order of 10 -11 sec. The observed slow relaxation near the transition temperature is accounted for as due to the thermodynamical slowing down process of the correlated fluctuation of polarization. The monodispersive character is discussed in terms of the long range natu...