Abstract
Critical polarization fluctuations in the nonpolar phase of a ferroelectric have been determined self-consistently using a correlated effective-field theory of ferroelectricity. Static correlations take the form of highly developed ferroelectric chains along an incipient polar direction, with interchain correlations being relatively very weak and of either sign. Neither interchain nor interchain correlations exhibit an exponential decay at large distances and a unique definition of correlation length is correspondingly difficult to obtain. The new statistical theory is able to describe phase transitions of both displacement and order-disorder character and predicts a paraelectric susceptibility divergence as $t=T\ensuremath{-}{T}_{C}\ensuremath{\rightarrow}0$ of the form $\frac{[\mathrm{ln}(\frac{1}{t})]}{t}$ and a specific heat going as $A\ensuremath{-}[\frac{{B}^{\ensuremath{'}}}{\mathrm{ln}(\frac{1}{t})}]$, where $A$ and ${B}^{\ensuremath{'}}$ are constants. These forms are to be compared with the Curie-Weiss susceptibility and the logarithmic divergence of specific heat which follow from the commonly used random-phase approximation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.