Large electrostrictive strain in lead-free Bi0.5Na0.5TiO3-BaTiO3-KNbO3 ceramics

In the present work, (1-x)(0.935Bi(0.5)Na(0.5)TiO(3)-0.065BaTiO(3))-xKNbO(3) (BNT-BT-KN, BNT-BT-100xKN) ceramics with x ranging from 0 to 0.1 were prepared by the conventional ceramic fabrication process. A large electrostrictive coefficient of similar to 10(-2) m(4) C-2 is obtained with the composition x ranging from 0.02 to 0.1, which is close to the well-known electrostrictive material Pb(Mg1/3Nb2/3)O-3. Under an electric field of 4 kV/mm, the electrostrictive strain can reach as high as 0.08%. Besides, the electric field induced strain behavior indicates a temperature independent behavior within the temperature range of 20 to 150A degrees C. The large electrostrictive strain is suggested to be ascribed to the formation of non-polar (NP) phase developed by the KNbO3 substitution, and the high electrostrictive coefficient of BNT-BT-KN ceramics makes them great candidates to be applied in the new solid-state actuators.