The Effects of the interfacial Pseudo-spin Coupling Fluctuation on the Dielectric Property of a Ferroelectric Superlattice

TL;DR

This study uses effective-field theory to analyze how fluctuations in interfacial pseudo-spin coupling affect the dielectric properties of ferroelectric superlattices, revealing increased susceptibility and shifts in phase transition behavior.

Contribution

It introduces a theoretical investigation of interfacial coupling fluctuations on ferroelectric superlattices using the transverse Ising model, highlighting their impact on susceptibility and phase transition temperature.

Findings

Interfacial coupling fluctuations increase susceptibility at low temperatures.

Strong interfacial coupling fluctuations decrease phase transition temperature.

Susceptibility peak shifts to larger superlattice periods with increased fluctuations.

Abstract

Using effective-field theory with correlations, we investigate the effects of interfacial pseudo-spin coupling fluctuations on the susceptibility and polarization of ferroelectric superlattices within the framework of transverse Ising model. It is found that the interfacial coupling fluctuations increase the susceptibility in the low temperature region. For a strong interfacial coupling, the phase transition temperature decreases with the strength of fluctuations of the interfacial coupling. The dependence of the susceptibility on the superlattice period of $BaTiO_{3}/SrTiO_{3}$ are plotted for different interfacial coupling fluctuations strength. At room temperature, when the interfacial coupling fluctuation increases, the peak position of the susceptibility will shift to a large superlattice period.