The Mystery of Dimensional Effects in Ferroelectricity

The dimensional effect on ferroelectricity is a subject of long-understanding fundamental interest. While the low-dimensional finite ferroelectric structures are committed to the potential increase in electronics miniaturization, these anticipated benefits hinged on the existence of stable ferroelectric states in low-dimensional structures. This phenomenon can be understood from the point of basic physics. This chapter reviews the literature on the finite-size effects in ferroelectrics, emphasizing perovskite and polyvinylidene-based polymer ferroelectrics having technological importance. The reviewed data revealed that despite critical dimensionality being predicted in ferroelectrics, polarization switching phenomenon is possible in as thin as one monolayer film, at least in the case of P(VDF-TrFE) Langmuir–Blodgett thin film with stabilized functional properties. The roles of the depolarization field, electrode interfaces, domain wall motion, etc. in controlling the measured ferroelectric properties have been discussed. Further, the observed deviation from the bulk properties is explained based on both experimental and theoretical modeling.