Dielectric, optical, piezoelectric and ferroelectric studies of NBT-BT ceramics near MPB

Solid solutions of the lead free (1-x)Na0.5Bi0.5TiO3-xBaTiO(3)/NBT-xBT (where x=0.05, 0.06, 0.07, and 0.08) ferroelectric ceramics were synthesized in single perovskite phase by solid state reaction route. Higher values of remnant polarization (P-r) similar to 31.71 mu C/cm(2), dielectric constant (epsilon(r)) similar to 5067, piezoelectric coefficient (d(33)) similar to 105 pC/N, electromechanical coupling coefficient (k(p)) similar to 21.17 and maximum induced strain% of similar to 0.45 were obtained in the x=0.07 NBT-xBT composition. The bipolar fatigue behavior of the NBT-xBT (x=0.05, 0.06, 0.07, and 0.08) ceramics was carried out by the remnant polarization vs. number of cycles (up to 10(9)) study. Optical band gap of all the NBT-xBT ceramics was found to be similar to 3 eV. Excellent dielectric, piezoelectric and ferroelectric properties suggested that the x=0.07 is the actual MPB composition of the NBT-xBT system. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.