Exploring the high-performance (1-x)BaTiO3-xCaZrO3 piezoceramics with multiphase coexistence (R-O-T) from internal lattice distortion and domain features

Although the multiphase coexistence has made great achievements in improving the piezoelectric properties of barium titanate-based (BT) ceramics, the problems such as internal lattice distortion and external physical mechanism at the phase boundary still remain. Here, we have studied the phase structure, atomic parameters and domain structure of (1-x)BaTiO3-xCaZrO3 (abbreviated as BT-xCZ) ceramics. By regulating the phase transition temperatures, the rhombohedral-orthorhombic-tetragonal (R-O-T) multiphase coexistence (x = 0.06) is realized at room temperature. Notably, high piezoelectric constant of d33 ∼ 445 ± 20 pC/N and large electromechanical coupling factor of kp = 55% are obtained at x = 0.06. With the doping of CaZrO3 (CZ), the lattice of ceramics is distorted, thereby increasing the ferroelectricity and piezoelectricity. Importantly, the domain structure of BT-xCZ ceramics observed by the acid etching technology further proves that the high piezoelectricity is attributed to the multiphase coexistence and reduction of the domain wall energy density.