Giant strain in lead-free piezoceramics Bi0.5Na0.5TiO3-BaTiO3-K0.5Na0.5NbO3 system

Piezoelectric actuators convert electrical into mechanical energy and are implemented for many large-scale applications such as piezoinjectors and ink jet printers. The performance of these devices is governed by the electric-field-induced strain. Here, the authors describe the development of a class of lead-free (0.94-x)Bi0.5Na0.5TiO3-0.06BaTiO(3)-xK(0.5)Na(0.5)NbO(3) ceramics. These can deliver a giant strain (0.45%) under both unipolar and bipolar field loadings, which is even higher than the strain obtained with established ferroelectric Pb(Zr,Ti)O-3 ceramics and is comparable to strains obtained in Pb-based antiferroelectrics.