Basic characteristics of piezoelectric ceramics

Piezoceramic is a kind of piezoelectric ceramic material with piezoelectric properties. The main difference from the typical piezoelectric quartz crystal, which does not contain ferroelectric components, is that the crystalline phase, which constitutes its main component, is ferroelectric. Since ceramics are polycrystalline aggregates with random grain orientation, the spontaneous polarization vectors of each ferroelectric grain are also chaotic. In order to make the ceramics exhibit a macro piezoelectric characteristic, it is necessary to polarize it under a strong dc electric field after the piezoelectric ceramic is burned and the end face is re electrode, so that it can be polarised. The polarization vectors of the chaotic orientation are preferred in the direction of the electric field. The piezoelectric ceramics after polarization treatment will retain a certain macro residual polarization after the electric field is cancelled, thus making the ceramics have certain piezoelectric properties. The biggest characteristic of piezoelectric ceramics is piezoelectric, including positive piezoelectric and inverse piezoelectric. The positive piezoelectricity refers to the polarization caused by the relative displacement of the positive and negative charge center in the medium under the action of the mechanical force, which leads to the opposite bound charge in the surface of the dielectric.