Domain structure and piezoelectric property of Ba _0.85 Ca _0.15 Zr _0.1 Ti _0.9 O ₃ ceramics polarized by pulse‐poling method

Abstract The domain structures and piezoelectric properties of polycrystalline orthorhombic 0.5(Ba 0.7 Ca 0.3 )TiO 3 ‒0.5Ba(Zr 0.2 Ti 0.8 )O 3 (BCZT50) polarized by various poling methods were investigated. Semiquantitative analysis using a scanning electron microscope revealed that the domain size d D of BCZT50 polarized by alternating current poling (AC‐poling, d D = 0.16 µm) and unipolar pulse poling (Uni‐poling, d D = 0.16–0.36 µm) were finer than those in samples polarized by conventional direct current poling method (DC‐poling, d D = 0.32 µm). Although the domain size of the Uni‐poled sample was intermediate among the three different poling methods, the highest piezoelectric charge coefficient d 33 of 339 pC/N was achieved by Uni‐poling with a peak electric field E pk = 0.50 kV/mm ( E rms = 0.29 kV/mm), 20 pulse cycles, and a frequency of 2 Hz. These results are discussed in conjunction with polarization–electric field hysteresis and dielectric properties, indicating that pulse‐poling treatment is a promising approach to modify the domain structure and piezoelectric properties of BCZT50.