2. Lead-free piezoelectric materials, alternatives to PZT

Research into lead-free piezoelectric materials is driven by the need to find materials that are less harmful than PZT, but also to find piezoelectric materials that can be used in areas where PZT cannot, such as very high-temperature applications (> 350°C).

In 2004, a large piezoelectric coefficient d ₃₃ = 416 pC · N ^–1 , comparable to that of PZT was obtained by Saito et al. , in textured potassium...