The influence of Initial Mechanical, Electrostatic and Temperature Effects on the Properties of Pyropiezoelectrics of the Hexagonal System

The work is aimed at studying the effect of initial mechanical, temperature and electrostatic influences on the change in the deformed state and physical properties of thermoelectroelastic materials, which in their natural state belong to the materials of the 6mm hexagonal symmetry class. It is assumed that the initial deformed state induced in the material is homogeneous, the initial temperature effects do not exceed the temperature of phase transitions, and the initial electrostatic field is specified by the strength vector. The study is based on the use of linearized constitutive relations, equations of motion of thermoelectroelastic media, electrostatic equations and heat propagation equations obtained within the framework of the theory of imposing small deformations on finite ones. Matrix representations of tensors of elastic and piezoelectric moduli of a prestressed material are presented, clearly illustrating the influence of initial mechanical and temperature, as well as electrostatic influences on the properties of a pyropiezoelectric material. Within the framework of the proposed approach, using CdSe as an example, the separate and combined influence of the type and magnitude of initial mechanical stresses, electrical and thermal effects on the nature of induced deformations and transformation of the properties of the material was studied. The types of mechanical influences leading to maximum values of electrical induction are determined. The influence of the nature of temperature effects in the absence of initial mechanical stresses on the magnitude and direction of the electrical induction vector is shown. The patterns of influence of the initial high-intensity electrostatic field on the elastic and piezoelectric properties of the material have been revealed. The research results are presented in the form of graphs and may be of particular interest in the development, design and optimization of pyropiezoelectric materials used in the creation of new micro- and nano-sized devices.

thermoelectroelasticity, initial mechanical stress, preheating, initial deformed state, electrostatic field strength, electrical induction