High piezoelectric response in the new coexistent phase boundary of 0.87BaTiO3-(0.13-x)BaZrO3-xCaTiO3

An investigation of the coexistent ferroelectric phase was carried out on the ternary system of 0.87BaTiO(3)(0.13-x)BaZrO3-xCaTiO(3) [abbreviated as BT-BZ-xCT (where 0.00 <= x <= 0.13)]. Temperature-, frequency dependent dielectric data, electric field-dependent strain and polarization as a function of composition are presented in order to understand the relationships of structure-properties and find the high piezoelectric response in this system. Results showed that ceramics in the composition range of 0.00 <= x <0.04 were of a rhombohedral structure and transformed into a tetragonal structure at x > 0.06. The multiphase coexistence of the rhombohedral and tetragonal phase in this system was identified at x = 0.06. A large, virtually hysteresis-free electric field induced strain of 023% was achieved with the composition, x = 0.06, at 40 kV/cm on the boundary between rhombohedral and tetragonal phase. This relates to an extraordinarily high and normalized piezoelectric coefficient (S-max/E-max) of 1280 pm/V, which was reached at a low electric field applied at 10 kV/mm. These results indicated that a high piezoelectric response may stem primarily from the rhombohedral-tetragonal phase boundary, due to greater lattice softening and reduced energy barriers for polarized rotation. (C) 2015 Elsevier Ltd. All rights reserved.