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

Highlights: • The new coexistent phase composition in the 0.87BaTiO₃–(0.13-x)BaZrO₃–xCaTiO₃ system was identified. • A high normalized piezoelectric coefficient (S_max/E_max) of 1260 pm/V was achieved at the coexistent phase composition. • A composition–temperature ferroelectric phase diagram was proposed in this work. - Abstract: An investigation of the coexistent ferroelectric phase was carried out on the ternary system of 0.87BaTiO₃–(0.13-x)BaZrO₃–xCaTiO₃ [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 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 0.23% 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.