Broadband Electromechanical Spectroscopy: characterizing the dynamic mechanical response of viscoelastic materials under temperature and electric field control in a vacuum environment

摘要: The viscoelasticity of a variety active materials is controllable, e.g., by the application electric or thermal fields. However, their viscoelastic behavior cannot be fully explored current methods due to limitations in control mechanical, electrical, and fields simultaneously. To close this gap, we introduce Broadband Electromechanical Spectroscopy (BES). For specific apparatus developed, specimens are subjected bending torsional moments with frequencies up 4 kHz amplitudes 10−4 Nm (the method sufficiently general allow for higher wider frequency ranges). Deflection/twist measured applied contactless fashion minimize influence compliance spurious damping. Electric via surface electrodes at 10 Hz 5 MV/m. Experiments performed under vacuum remove noise from surrounding air. Using BES, dynamic stiffness damping torsion ferroelectric ceramic, lead zirconate titanate, were room temperature, while applying large, cyclic induce domain switching. Results reveal large increases specimen’s capacity softening modulus during effect occurs over wide ranges mechanical permits lowering resonance frequencies. This promises potential using ferroelectrics vibration beyond linear piezoelectricity. More generally, BES helps improve understanding microstructure kinetics (such as switching) how it relates macroscopic response materials.