Domain structures and nonlinear mechanical deformation of soft Pb(ZrxTi1−x)O3 (PZT) piezoelectric ceramic fibers

The nonlinear mechanical deformation of two tetragonal variants of soft, morphotropic lead zirconate–titanate Pb(ZrxTi1−x)O3 (PZT) piezoelectric ceramic fiber was correlated with studies of the crystal structure, domain structure, and microstructure. Fibers with dense hierarchical microtwin structures having spatial dimensions of ∼10 nm showed an additional mode of stress accommodation as evidenced by a larger strain accumulation and greater anelastic response relative to fibers with conventional twin structures consisting primarily of 90° and 180° tetragonal ferroelectric–ferroelastic domains. The differing natures of the domain structures in the two variants of soft PZT materials were associated with differences in the defect chemistry. The observed sensitivity of the nonlinear mechanical deformation to the presence of spatially inhomogeneous microtwin structures is expected to be of particular importance in the engineering of flexible fiber composites and other transducers based on soft PZT piezoelectric materials intended for use under conditions of high amplitude dynamic deformation.