Direct observation of domain wall motion and lattice strain dynamics in ferroelectrics under high-power resonance

Abstract

Domain wall motion and lattice strain dynamics of ferroelectrics at resonance were simultaneously measured by combining high-power burst excitation and in situ high-energy x-ray diffraction. The increased loss at high vibration velocity was directly related to the increased domain wall motion, driven by dynamic mechanical stress. A general relationship between the microstructural strain contributions and macroscopic electromechanical behavior was established, allowing the prediction of high-power stability of ferroelectric materials. The results indicate that the materials' stability during high-power drive is predominantly related to the basic chemical composition, while the piezoelectric hardening mechanisms mainly influence the small-signal behavior.

Influence of Zn2+ doping on the morphotropic phase boundary in lead‐free piezoelectric (1 – x)Na1/2Bi1/2TiO3‐xBaTiO3

“…Note that although charge compensation via oxygen vacancy formation is assumed to be dominant in NBT‐based materials, evaporation of bismuth or the change of Ti 4+ to Ti 3+ are also possible mechanisms for charge compensation. In doped systems, the pinning of domain walls and hence the reduction of domain wall mobility have been ascertained to be derived from three possible mechanisms: volume effect, domain wall effect, and interface effect 24,56 . This is usually evidenced by a shift in the polarization hysteresis loop along the electric field axis and can be quantified by the internal bias field E bias 57–59 .…”

“…In doped systems, the pinning of domain walls and hence the reduction of domain wall mobility have been ascertained to be derived from three possible mechanisms: volume effect, domain wall effect, and interface effect. 24,56 This is usually evidenced by a shift in the polarization hysteresis loop along the electric field axis and can be quantified by the internal bias field E bias . [57][58][59] A ferroelectrically hardened material is associated with reduced electromechanical losses, 56 which result in a higher mechanical quality factor.…”

“…This results in a nonlinear temperature increase of the ceramic, when operated at these velocities. [22][23][24] Certain applications such as high-power ultrasonics demand compositions with high mechanical quality factors. Ferroelectric hardening is a common approach to increase the mechanical quality factor of piezoelectric materials and several concepts have been reported to harden the NBT-BT system.…”

“…PZT‐based materials suffer from a decreasing mechanical quality factor Q m at high vibration velocities. This results in a nonlinear temperature increase of the ceramic, when operated at these velocities 22–24 . Certain applications such as high‐power ultrasonics demand compositions with high mechanical quality factors.…”

Measurement System for Piezoelectric Resonance Impedance Spectroscopy Under Combined AC and High-Voltage DC Loading

“…The highest piezoelectric properties are obtained in ferroelectric materials, where the electromechanical conversion mainly originates from the crystal lattice and ferroelectric domains [2,3]. While the latter are an important and often dominant contribution to strain, they are also largely responsible for hysteretic behavior and losses [4,5]. These are detrimental for the use of piezoelectrics under near-resonance conditions, e.g., in ultrasonic motors and transducers.…”