The effect of hydrostatic pressure on thermodynamic characteristics of NH$_3$CH$_2$COOH$\cdot$H$_2$PO$_3$ type ferroelectric materials

TL;DR

This study investigates how hydrostatic pressure influences the thermodynamic and dielectric properties of NH$_3$CH$_2$COOH$dot$H$_2$PO$_3$ ferroelectric materials using a modified cluster model.

Contribution

The paper introduces a model incorporating piezoelectric coupling to analyze pressure effects on ferroelectric properties, aligning well with experimental data.

Findings

Hydrostatic pressure shifts phase transition temperatures.

Pressure affects dielectric permittivity and polarization.

Model accurately predicts experimental observations.

Abstract

The model of NH$_3$CH$_2$COOH$\cdot$H$_2$PO$_3$, modified by taking into account the piezoelectric coupling between the ordering structure elements and the strains $\varepsilon_i$, $\varepsilon_j$, is used for investigation of the effects that appear under external pressures. Within two-particle cluster approximation, the components of polarization vector and static dielectric permittivity tensor of the mechanically clamped and free crystals, their piezoelectric and thermal characteristics are calculated. The effect of hydrostatic pressure on the phase transition and the calculated physical characteristics of the crystal is studied. A good quantitative description of experimental data for these crystals is obtained.