High piezoelectric response in lead free 0.9BaTiO3-(0.1-x)CaTiO3-xBaSnO3 solid solution

Lead free piezoelectric in the ternary system of 0.9BaTiO3-(0.1-x)CaTiO3-xBaSnO3 [BCT-xBS], where x = 0.00-0.075, was fabricated via a conventional solid state reaction. The effect of substituting BCT with BS on the crystal structure as well as dielectric, ferroelectric and strain behavior was investigated systematically in order to search for outstanding actuating performances in lead free piezoelectric ceramics. A ferroelectric phase diagram of BT-CT-BS was established in this work, and a multi-ferroelectric phase composition was designed near ambient temperature, based on an established phase diagram. The BS substitute depressed the ferroelectric-paraelectric phase temperature slightly and raised the transition temperatures of O-T phase transformations, thus, the orthorhombic phase could be stabilized above the ambient temperature with x > 0.05. As a result, the polymorphic phase composition showed outstanding piezoelectric values of kp = 41.7%, d33 = 469 pC/N and d33* = 1335 pm/V@10 kV/cm, which are suitable for lead free piezoelectric actuator applications.