A Novel BiFeO3-BaTiO3-BaZrO3 Lead-Free Relaxor Ferroelectric Ceramic with Low-Hysteresis and Frequency-Insensitive Large Strains

A novel (0.67-x) BiFeO3-0.33BaTiO(3)-xBaZrO(3) lead-free relaxor ferroelectric ceramic was developed by a solid-state reaction method. Measurements of temperature-dependent dielectric permittivity and the polarization/ strain hysteresis loops demonstrated an obvious evolution of dielectric relaxor behavior at room temperature (RT) from nonergodic to ergodic states. A significantly enhanced electrostrain of similar to 0.37% at 7 kV/ mm with a relatively small hysteresis of similar to 39% and a low-frequency sensitivity was found at x = 0.04, showing large potential for actuator applications. This was basically attributed to a rapid response of forward and backward switching between ergodic and ferroelectric phases owing to similar free energies and large local random fields.