Exceptionally High Piezoelectric Coefficient and Low Strain Hysteresis in Grain-Oriented (Ba, Ca)(Ti, Zr)O₃ through Integrating Crystallographic Texture and Domain Engineering

Both low strain hysteresis and high piezoelectric performance are required for practical applications in precisely controlled piezoelectric devices and systems. Unfortunately, enhanced piezoelectric properties were usually obtained with the presence of a large strain hysteresis in BaTiO₃ (BT)-based piezoceramics. In this work, we propose to integrate crystallographic texturing and domain engineering strategies into BT-based ceramics to resolve this challenge. [001]_c grain-oriented (Ba_0.94Ca_0.06)(Ti_0.95Zr_0.05)O₃ (BCTZ) ceramics with a texture degree as high as 98.6% were synthesized by templated grain growth. A very high piezoelectric coefficient (d₃₃) of 755 pC/N, and an extremely large piezoelectric strain coefficient (d₃₃* = 2027 pm/V) along with an ultralow strain hysteresis (H_s) of 4.1% were simultaneously achieved in BT-based systems for the first time, which are among the best values ever reported on both lead-free and lead-based piezoceramics. The exceptionally high piezoelectric response is mainly from the reversible contribution, and can be ascribed to the piezoelectric anisotropy, the favorable domain configuration, and the formation of smaller sized domains in the BCTZ textured ceramics. This study paves a new pathway to develop lead-free piezoelectrics with both low strain hysteresis and high piezoelectric coefficient. More importantly, it represents a very exciting discovery with potential application of BT-based ceramics in high-precision piezoelectric actuators.