Influence of uniaxial and hydrostatic pressures and a longitudinal electric field on the thermodynamic characteristics of the quasi-one-dimensional ferroelectric CsH₂PO₄

Abstract

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 eective dipole moments of pseudospins on the order parameters, which enables us to coordinate the values of the eective 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 eld approximation for the long-range interactions, the behavior of spontaneous polarization, longitudinal dielectric permittivity, piezoelectric and elastic characteristics, and molar heat capacity under the inuence of uniaxial and hydrostatic pressure and a longitudinal electric eld are investigated.

Effect of hydrostatic pressure on dynamic dielectric characteristics of CsH2PO4 ferroelectric

“…In [23][24][25][26], there is proposed a two-sublattice pseudospin model of the deformed crystal CDP, in which the interactions between the nearest pseudospins in the chain are considered in the mean field approximation. In this case, the interaction parameters are linear functions of the strains 𝑢 𝑗 .…”