Traditional piezoelectric ceramics are mainly composed of lead containing lead zirconate titanate (PZT) materials, with the main component being lead oxide (over 60-70%). Lead oxide is a volatile toxic substance that can cause damage to humans and the ecological environment during production, use, and disposal. The volatilization of PbO can also cause deviation in the stoichiometric ratio of ceramics, reducing product consistency and repeatability, requiring sealed sintering to increase costs.

Therefore, the research and development of high-performance lead-free piezoelectric ceramics has significant scientific significance and urgent market demand, and has gradually become a research hotspot.

According to different criteria, the classification of various non lead based piezoelectric ferroelectric ceramic systems varies slightly. Summarize various classifications as follows.

Perovskite structure

The name of perovskite structure comes from the structure of CaTiO3, a mineral with the chemical formula ABO3. Many important piezoelectric ceramics (including lead based and non lead based ceramics) exist in perovskite structure.

Mainly including barium titanate (BaTiO3) based (BT based) lead-free piezoelectric ceramics, bismuth sodium titanate [(Bi0 5Na0.5) TiO3 based (BNT based) lead-free piezoelectric ceramics and alkali metal potassium sodium niobate [(K, Na) NbO3] based (KNN based) lead-free piezoelectric ceramics.

tungsten bronze

This type of crystal structure is similar to perovskite structure (therefore, it is sometimes not listed separately when dividing the system).

Mainly including lead-free piezoelectric ceramics represented by Sr1-xBaxNb2O6 and NaBa2Nb5O15 systems.

bismuth layer-structured

This type of piezoelectric ceramic is a compound with a layered structure, which is composed of bismuth layered compound layers and lattice layers of perovskite structure interspersed and overlapped.

Mainly including bismuth layered lead-free piezoelectric ceramics represented by bismuth titanate (Bi4Ti3O12), bismuth calcium titanate (CaBi4Ti4O15), and bismuth strontium titanate (SrBi4Ti4O15).

FBELE focuses on the research and development of BaTiO3 Piezo ceramic discs or rings, leading the world at an advanced level