Self-field effect, ΔP, and thermodynamic stability of spontaneous polarization in thin ferroelectric platelets

Finite size effect of thin ferroelectric platelets is investigated using a Ginzburg-Landau thermodynamic theory, where spontaneous polarization (P) is an order parameter. The theory is directly applicable to metal/ferroelectric/insulator/semiconductor heterostructures. Furthermore, we show that an inhomogeneous P (ΔP) or a relaxation at the ferroelectric surface is effectively the same as the existence of a surface dead layer and is modeled by ferroelectric/semiconductor or ferroelectric/insulator heterostructure. Noting this result and considering the effect of the surface dead layer, the finite size effect and the P-induced field effect in metal/ferroelectric/metal and a thin ferroelectric platelet is discussed. Additionally, rigorous numerical results are also present to supplement our recent publication.