Measured Lamb wave radiation patterns from ⟨011⟩ Mn-PMN-PZT relaxor ferroelectric disks on an isotropic plate

• Published in: Applied physics letters 2018-09, Vol.113 (12)
• Main Authors: Vien, B. S., Moss, S. D., Chiu, W. K., Thornton, J., Rosalie, C., Rajic, N., Doughney, T. F., Kissick, H. J.
• Format: Article
• Language: English
• Subjects: Actuators; Applied physics; Disks; Electric field strength; Fast Fourier transformations; Ferroelectric materials; Ferroelectricity; Fourier transforms; Lamb waves; Lead; Lead zirconate titanates; Piezoelectricity; Relaxors; Single crystals
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5044671

Three-dimensional laser Doppler vibrometry is used to quantify the modal composition of the guided plate waves generated by relaxor ferroelectric disk actuators of a ⟨011⟩ poled Mn-Pb(Mg1/3Nb2/3)O-lead zirconate titanate (PZT) single crystal and ⟨100⟩ poled piezoelectric PZT, bonded to an isotropic plate. Disk actuators are excited using a 5.5 cycle Hann-windowed voltage tone-burst at centre frequencies of 100, 200, and 300 kHz. Measured wave fields are processed using a two-dimensional fast Fourier transform to determine the radiation pattern of each contributing mode. For the same applied electric field strength, the single crystal actuators are shown to produce significantly larger wave amplitudes and one additional wave mode, the shear horizontal, as compared with PZT actuators. The wave-mode radiation patterns are shown to be anisotropic, suggesting that the classical theory describing guided-wave modal excitability may need to be revised for these materials.