Investigation of ferroelectric order-disorder type compounds with asymmetric double-well potential

The Mitsui model for the order-disorder type ferroelectrics is studied within the mean field approximation. The phase diagram of the model is obtained, its dependence on the transverse field is obtained. A scheme of setting the values of the model parameters is proposed; all the dielectric characteristics of Rochelle salt are calculated with the found parameters. Within the Mitsui model we study the physical characteristics of RbHSO4 type crystals; the found values of the model parameters provide a good description of both dielectric and thermodynamic properties of these compounds.