Saha, Dipika and Sen, Amarnath (1995) Low-frequency dispersion extended to higher frequencies - a new look at relaxor behavior. Philosophical Magazine Letters, 71 (6). pp. 367-376. ISSN 0950-0839

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A new theoretical framework and its experimental verification are presented in order to understand and generalize the dielectric response for relaxer ferroelectrics. By considering the fluctuating nanodomains of relaxors as fluctuating `giant dipoles' we argue that the relaxer effect is indeed a low-frequency dispersion (LFD) phenomenon extended to the r.f. range. Because of the presence of disorder in relaxer ferroelectrics, configurational tunnelling plays an important role; we show that all the conditions necessary for LFD exist in the relaxers and at the same time we provide sufficient reasons to establish why LFD in relaxers is extended as well as prominent in the r.f. range. Our model explains the importance of random electric fields for exhibiting relaxer behaviour. Finally we substantiate our model by showing that dielectric constant and dissipation values as well as dispersion in lead magnesium niobate relaxer ferroelectrics are enhanced in a humid atmosphere in agreement with many well known adsorbate systems showing LFD.

Item Type: Article
Subjects: Electronics
Depositing User: Bidhan Chaudhuri
Date Deposited: 21 Aug 2012 10:33
Last Modified: 23 Mar 2016 12:37

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