# Influence of the uniaxial stress $p_2$ and transverse fields $E_1$ and $E_3$ on the phase transitions and thermodynamic characteristics of GPI ferroelectric materials

2021;
: pp. 454–464

Revised: June 26, 2021
Accepted: July 05, 2021
1
Institute for Condensed Matter Physics
2
Lviv Polytechnic National University
3
Institute for Condensed Matter Physics
4
Lviv Polytechnic National University

A modified GPI model that accounts for the piezoelectric coupling between the ordered structural elements and the strains $\varepsilon_j$ has been used for studing of effects arising in GPI ferroelectrics under the action of the uniaxial stress $p_{2}$ and electric fields $E_1$ and $E_3$.  The  polarization vectors and components of static dielectric permittivity are calcucated in the two-particle cluster approximation for mechanically clamped  crystal, and piezoelectric and thermal parameters are also determined.  The influence of the simultaneous action of the stress $p_{2}$ and fields $E_1$ and $E_3$ on the phase transition and physical characteristics of GPI crystal has been studied.

Mathematical Modeling and Computing, Vol. 8, No. 3, pp. 454–464 (2021)