Reversible Domain-Wall-Motion-Induced Low-Hysteretic Piezoelectric Response in Ferroelectrics

The mobility of domain walls under an external stimulus plays a crucial role in the piezoelectricity of ferroelectric materials, which usually manifests itself as an irreversible and hysteretic characteristic. Herein, we report a reversible domain-wall motion that contributes almost 55% to the significant piezoelectric response (d33 = 730 pm/V) with low strain hysteresis (H_S = 10.76%) at a composition close to the morphotropic phase boundary (MPB) in a (1 - x)Ba(Ti_0.88Sn_0.12)O₃-x(Ba_0.7Ca_0.3)TiO₃ system. Such a reversible domain-wall motion is evidenced by the piezo response force microscopy measurement. Moreover, transmission electron microscopy observation indicates a hierarchical domain structure for MPB composition (x = 0.28), and the associated high-resolution image suggests the presence of spatial local chemical heterogeneity. Combined with phase field modeling, we reveal that the reversible domain-wall motion is attributed to the asymmetric landau free energy profile as a result of morphotropic phase boundary incorporation with the local heterogeneity. Our work may advance the development of low-hysteretic piezoelectric materials in the application of energy converter or other devices with low energy consumption and high precision.