Processing and characterizations of BNT-KNN ceramics for actuator applications

BNT-KNN powder (with composition 0.93Bi0.5Na0.5TiO3-0.07K0.5Na0.5NbO3) was\n synthesized as a single perovskite phase by conventional solid state reaction\n route and dense ceramics were obtained by sintering of powder compacts at\n 1100°C for 4 h. Dielectric study confirmed relaxor behaviour, whereas the\n microstructure study showed sharp cornered cubic like grains with an average\n grain size ~1.15 μm. The saturated polarization vs. electric field (P-E)\n hysteresis loops confirmed the ferroelectric (FE) nature while the butterfly\n shaped strain vs. electric field (S-E) loops suggested the piezoelectric\n nature of the BNT-KNN ceramic samples. Maximum electric field induced strain\n of ~0.62% suggested the usefulness of this system for actuator applications.