06-18U

Within the framework of two-sublattice Ising model with taking into account short-range and long-range interactions and the piezoelectric interaction with the shear strain within two-particle cluster approximation, the dielectric, piezoelectric and elastic characteristics of simple model of piezoelectric are calculated in the cases of polar and non-polar ordering. Taking into account a dynamics of piezoelectric deformation, the phenomena of crystal clamping by high frequency electric field and piezoelectric resonance are described. Ultrasound attenuation is calculated, peculiarities of its temperature dependence near the phase transition points are investigated. Detailed numerical analysis of the obtained results is carried out.