Invited
Two dimensional ferroelectrics

The discovery of two dimensional ferroelectrics was done in 1998 [1].They reveal non-domain switching because their thickness is less than the domain nucleus. Therefore the kinetics of switching is described not by KAI (Kolmogorov-Avrami-Ishibashi) theory,but by Lagrange equation: kdP/dt= -dF/dP [1]

where P is spontaneous polarization,F is free energy and k is damping coefficient.The solution of [1] for phase transition of first order gives: switching time tau:
1/tau=1/g (E/Ec-1),where g depends on k and Landau-Ginzburg coefficients [2] Dependence of tau from film thickness permits to experimentally obtain the size of domain nucleus.

1 Bune A.Fridkin V.Ducharme S.et al Nature (London) 391,874 (1998)
2.Vizdrik G.Ducharme S.Yudin S.Fridkin V.,Phys.Rev.B68,094113(2003)
3 Fridkin V.Ducharme S.Ferroelectricity at the Nanoscale,,Springer Verlag,2014