Development of piezoelectric ceramic materials

About advantages of piezoelectric ceramics, piezoelectric energy harvesting has low price and easy mass production, which have been widely used in the various fields of social production. Especially in the ultrasonic field and the field of electronic science and technology, low frequency piezoelectric tubes have gradually been used for an absolute dominant position, such as medicine. for industrial ultrasonic testing, underwater sound detection, piezoelectric transducers, ultrasonic motors, display devices, electronically controlled multicolor filters, etc. However, in the practical components, different applications of piezoelectric plate crystal require different performance parameters for piezoelectric ceramic materials, which forces people to perform corresponding performance improvements on piezoelectric ceramic materials. At present, there are mainly two methods used at home and abroad: one is doping modification, PZT material piezo ceramic is to dope certain impurity ions; the other is to improve the preparation process. This article will provide a summary of the latest developments, research, applications and development trends of piezoelectric ceramic materials. The purpose is enable for relevant scientific research and teaching staff to notice new developments in the field and problems to be solved. 1, it is the basic properties of piezoelectric ceramics, characteristics of the mini piezo ceramic discs are positive piezoelectricity and reverse piezoelectricity.Positive piezoelectricity refers to the fact that certain dielectrics under the action of mechanical external forces, which cause a relative displacement of the positive and negative charge centers within the medium and cause polarization,it is resulting in the occurrence of oppositely bound charges within the surfaces of the dielectric. When the external force is not too large, its charge density is proportional to the external force, it is following the formula: δ=dT ,where δ is the surface charge density, d is the piezoelectric constant, and T is the elastic stress. It is positive piezoelectric effect and the inverse piezoelectric effect. Conversely, when an external electric field is applied to a piezo ceramic cylinder, the positive and negative charge centers in the dielectric are not only polarized due to relative displacement, but also the dielectric occurs due to this displacement. this effect is called inverse piezoelectricity. When the electric field is not very strong, the deformation is linear with the external electric field, following the formula: x → =dt E s → where dt is the piezoelectric strain constant, Es → the applied electric field, and x → the strain.