|
Journal of Physical Studies 14(1), Article 1701 [17 pages] (2010)
DOI: https://doi.org/10.30970/jps.14.1701 LONGITUDINAL DIELECTRIC, PIEZOELECTRIC, ELASTIC, AND THERMAL CHARACTERISTICS OF THE KH2PO4 TYPE FERROELECTRICSR. R. Levitskii1, I. R. Zachek2, A. S. Vdovych1, A. P. Moina1
1Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine |
 |
Within the framework of the modified proton ordering model for the KH$_{2}$PO$_{4}$ type with taking into account a linear in strain $ε _{6}$ contribution to the proton subsystem energy but without tunneling, in the four-particle cluster approximation we calculate the thermodynamic potentials of the system. Using the appropriate equations of state, we calculate spontaneous polarization, longitudinal dielectric permittivity of mechanically free and clamped crystals, their piezoelectric characteristics, elastic constants and molar specific heat. At the proper choice of the values of model parameters we obtain a good quantitative description of available experimental data for the K(H$_{1 - x}$D$_{x})_{2}$PO$_{4}$ type ferroelectrics.
PACS number(s): 77.80.-e, 77.84.-s, 77.84.Fa, 77.65.Bn