INFLUENCE OF UNIAXIAL AND HYDROSTATIC PRESSURES AND A LONGITUDINAL ELECTRIC FIELD ON THE THERMODYNAMIC CHARACTERISTICS OF THE QUASI-ONE-DIMENSIONAL FERROELECTRIC CsH2PO4.

We propose a two-sublattice proton ordering model for the quasi-one-dimensional CsH₂PO₄ ferroelectric with hydrogen bonds, which takes into account contributions to the energy of the proton subsystem that are linear in the lattice strains ε1, ε2, ε3, and ε5. The model also takes into account the dependence of the effective dipole moments of pseudospins on the order parameters, which enables us to coordinate the values of the effective dipole moments in the paraelectric and ferroelectric phases. Within this model in the two-particle cluster approximation for the short-range interactions and in the mean field approximation for the long-range interactions, the behavior of spontaneous polarization, longitudinal dielectric permittivity, piezoelectric and elastic characteristics, and molar heat capacity under the influence of uniaxial and hydrostatic pressure and a longitudinal electric field are investigated. [ABSTRACT FROM AUTHOR]