Piezoelectric properties of BaTiO3–CaTiO3–BaZrO3 ceramics with compositions near the morphotropic phase boundary

The phase diagram of BaTiO3–CaTiO3–BaZrO3 (BT–BZ–CT) ternary system with compositions near the morphotropic phase boundary (MPB) has been studied. Based on the phase diagram, the relationship between piezoelectric properties and energy barriers of BT–BZ–CT ceramics with compositions near the MPB has been studied. Experimental result indicates that the piezoelectric response is proportional to the energy barrier between tetragonal (T) and cubic (C) phases for the samples with the same phase composition. Furthermore, when the energy barrier is small enough, polarization intensity change of the phase transitions is the decisive factor for the huge piezoelectric response.