Low-frequency dispersion in volume and interfacial situations
Low-frequency dispersion in volume and interfacial situations
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体积和界面情况下的低频色散
DOI：
10.1007/bf00544672
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发表时间：
1991
影响因子：
4.5
通讯作者：
A. K. Jonscher
中科院分区：
文献类型：
--
作者：
A. K. Jonscher
描述了低频色散(LFD)这一普遍而鲜为人知的现象，并对各种介电和半导体系统的实验证据进行了总结。回顾了频域和时间域的行为，并指出非常高的电荷密度存储在低频率。强调了LFD与电化学反应之间的联系。讨论了可以看到LFD的物理条件，特别强调了界面过程和体积过程之间的区别。简要讨论了早期对类LFD现象的麦克斯韦-瓦格纳过程和接触的分形几何的解释，发现这些解释不足以解释观察到的事实。结论是，可能有不止一个物理或物理化学原因导致自然界中观察到的LFD现象的多样性，但它们的共同特征必须是与频率无关的损耗与偏振比。我们定义了一个“能量标准”，它为解释幂函数响应提供了物理基础，在此基础上，我们提出了一个新的具有广泛适用性的新的电化学模型，它给出了正确的动态响应，并且具有不需要巨大的电场来解释观察到的很高的电荷存储的优点。还需要进一步的关键实验研究来阐明剩下的问题。
The ubiquitous and little-understood phenomenon of low-frequency dispersion (LFD) is described and the experimental evidence for it is summarized for a variety of dielectric and semiconducting systems. Both frequency- and time-domain behaviour are reviewed and it is pointed out that very high charge densities are being stored at low frequencies. The connection between LFD and electrochemical reactions is emphasized. The physical conditions under which LFD can be seen are discussed with particular emphasis on the distinction between interfacial and volume processes. Earlier interpretations of LFD-like phenomena in terms of Maxwell-Wagner processes and fractal geometry of contacts are briefly discussed and found to be insufficient to account for the observed facts. It is concluded that there is likely to be more than one physical or physico-chemical cause giving rise to the variety of LFD phenomena observed in nature but their common feature must be a frequency independent ratio of loss to polarization. We define an “energy criterion” which gives a physical basis for the interpretation of power-law responses and on this basis we propose a new electrochemical model of very general applicability giving the correct dynamic response and having the advantage of not requiring enormous electric fields to account for the very high charge storage observed. Further critical experimental studies are required to elucidate the remaining questions.