The Ising model has been an important theoretical tool in the understanding of phase transitions in ferroelectric materials. We first review how it relates to the underlying physics of order-disorder phase transitions in these systems, as well as mean-field results for the spontaneous polarization and the dielectric constant near the critical temperature. For hydrogen-bonded ferroelectrics, a term of interaction with an external transverse field is necessary to account for proton tunneling between the two minima of a double-well potential. Finally, we discuss both experimental and theoretical results for the problems of proton-lattice interactions, central peak dynamics, dynamical behavior of pseudo-one-dimensional ferroelectrics and pressure effects on hydrogen bonded ferroelectrics.
