THE STUDY OF THE HYDROSTATIC PRESSURE EFFECT ON THE THERMODYNAMIC PROPERTIES OF THE ROCHELLE SALT NaKC$_4$H$_4$O$_6cdot$4H$_2$O

摘要

The effect of hydrostatic pressure on thermodynamic properties of Rs was theoretically considered within the framework of the Mitsui model adjusted by taking into account piezoelectric interaction with the shear strain $eps_4$. The approach, according to which theory model parameters are linearly dependent on hydrostatic pressure, was proposed for consideration. The calculations were carried out in molecular field approximation. Theoretical results for thermodynamic characteristics were compared to experimental data. Basing on theoretical study, the explanation for discrepancies in experimental data derived by different researchers for static dielectric permittivity of a free crystal was proposed. The increase of saturation polarization due to application of hydrostatic pressure is predicted.