Electric properties of high strain textured Na0.5Bi0.5TiO3-BaTiO3-K0.5Na0.5NbO3 thick films

Textured (1 - x)(0.94Na(0.5)Bi(0.5)TiO(3) - 0.06BaTiO(3)) - xK(0.5)Na(0.5)NbO(3) (abbreviated as NBT-BT-KNN) thick film on platinum substrate was prepared via tape casting method. The structure and electrical properties of the thick films were investigated. The results show that the thick films possess typical polycrystalline perovskite structures and the orientation degree reached to 75%. The remnant polarization (P-r) and coercive field (E-r) were optimized to 11.2 mu C/cm(2) and 12.8 kV/cm for x = 0.02 thick film. The dielectric properties of NBT-BT-KNN thick films as a function of temperature were also investigated. With the addition of KNN, the T-d (depolarization temperature) and T-c (Curie temperature) are all decreased. Meanwhile, the dielectric constant is increased with the addition of the KNN at room temperature. The piezoelectric constant of the thick film was calculated from unipolar electric field-induced strain curve. With the addition of KNN, the d(33) value increased and reached to the maximum value of 349 pm/V for x = 0.02 thick film. (C) 2011 Elsevier Masson SAS. All rights reserved.