The dielectric properties of piezoelectric ceramics

Piezoelectric ceramics is a kind of information which can transform the mechanical energy and electric energy into each other. Functional ceramic material has piezoelectric effect.Piezoelectric ceramic has dielectric property, elasticity and so on. It has been widely used in medical imaging, acoustic sensors, acoustic transducers, ultrasonic motors, etc. With the rapid development of modern electronic information technology, the development and exploration of piezoelectric ceramic materials with excellent performance have become the hot issues in various countries. At present, there are mainly two kinds of methods for performance improvement for piezo sounder PZT materials : one is doping modification, that is doping certain kinds of modified ions; the other is improving the preparation process. This review summarizes the recent research progress and the latest application of piezoelectric ceramic materials at home and abroad, including lead-containing piezoelectric ceramics and lead-free piezoelectric ceramics; and prospects for the future development of ultrasonic plate transducer.The purpose is to enable relevant research and teaching staff to notice new developments in the field and problems to be solved. The dielectric properties of piezoelectric ceramics reflect the response of the ceramic materials for the external electric field. Piezoelectric sensor circuit are usually expressed by the dielectric constant ε. In the external electric field is not too large, the dielectric response of the electric field can be linear relationship P = ε0 χ E, P is the polarization intensity, ε0 is the vacuum permittivity, ultrasonic atomizing piezoelectric  is the rate of polarization, E is the applied electric field. Piezoelectric ceramic components is different uses have different requirements on the dielectric constant of piezoelectric ceramics. For example, piezoelectric ceramic speakers and other audio components require a larger dielectric constant of ceramics, while high-frequency piezoelectric ceramic components requires a material with a smaller dielectric constant. The elastic coefficient of piezoelectric ceramics is a parameter that reflects the relationship between deformation and force of ceramics. Piezoelectric ceramic materials, like other elastomers, piezo block crystal is following the elastic stiffness constants called the elastomers in Hooke's law, X is stress and x is strain. For the piezoelectric body, due to the existence of piezoelectricity, the value of the elastic coefficient is related to the electrical boundary conditions.