Origin of giant dielectric response in ferroelectric thin film multilayers

Abstract

A thermodynamic theory of dielectric response in ferroelectric thin film multilayers is developed. The solution of Lame equation for static dielectric susceptibility has shown that susceptibility diverges at the transition temperature of the thickness induced ferroelectric phase. This divergence is shown to be the origin of the giant dielectric response observed in some multilayers. The theory gives an excellent fit to the temperature dependence of the giant susceptibility observed recently in multilayers of PbTiO₃-Pb_1-xLa_xTiO₃ (x = 0.28).

Key Words:

• susceptibility
• polarization
• phase transition
• ferroelectric film.