Multifunctional barium titanate ceramics via chemical modification tuning phase structure

Global environmental concerns on the toxicity of lead-based piezoelectrics impel the great mass fervor on investigations of lead-free alternatives. Barium titanate (BaTiO3, BT) ceramics, the first discovered perovskite ferroelectrics, were widely employed to fabricate dielectric capacitors from 1950s. Since a piezoelectric breakthrough was achieved via chemical modification, intensive researches have been performed embracing lead-free BT-based piezoelectrics and their extensional functionalities. In this review, we encompass the state-of-the-art progress on chemical modification tuning phase structure toward advanced electrical properties in BT-based ceramics. Generally, modulated regularity of cations substitution on phase transition is summarized and clarified. Then, we highlight the common methodologies of phase structure (phase boundary, relaxor phase, room-temperature phase transition, etc.) design for optimizing piezoelectricity, electrostrictive strain, electrocaloric, dielectric energy storage or permittivity performances, and cover the noticeable developments and relevant physical mechanisms. Finally, perspectives and challenges on future research issues are featured. This review proposes to exert the significant guidance and service for material design of BT-based and other lead-free perovskite materials with superior functionalities.