Fabrication and simulation of a piezoelectric PIN-PMN-PT thin film for ultrahigh-frequency ultrasonic transducers

Recently, ultrahigh-frequency (UHF) ultrasonic transducers (> 100 MHz) have been widely applied in research fields such as medical diagnostics, nondestructive testing, energy harvesting, and so on, due to their capability of creating high-resolution ultrasonic images and detecting micro-scale defects. To accomplish this, in this study, ternary Pb(In1/2Nb1/2)O-3 -Pb(Mg1/3Nb2/3)O-3-PbTiO3 (i.e., PIN-PMN-PT) polycrystalline single-phase thin film was fabricated for UHF ultrasonic transducers due to their extraordinary piezoelectric properties and electromechanical coupling coefficients. A trTlayered structure (of 1) aluminum substrate, 2) the PIN-PMN-PT thin film, and 3) a silver electrode) was used to create a PIN-PMN-PT thin film compatible with intense thermal treatment and having low cost. To analyze the performance of the newly developed PIN-PMN-PT thin film, data were collected on its crystallographic and piezoelectric characteristics, fabrication process, analysis of piezoelectric constants, and ultrasonic pulse-echo response waveforms according to different design conditions (various front matching layers, backing materials, and media). These data were provided by X-ray diffraction, X-ray fluorescence, X-ray reflectometry, field emission scanning electron microscopy, and polarization-electric field hysteresis curves. Moreover, pulse-echo simulation was conducted using PiezoCAD software based on the Krimholtz-Leedom-Matthaei model. The results showed that the proposed PIN-PMN-PT thin film exhibited ultrahigh-resonance frequencies of similar to 500 MHz. Ultimately, it was concluded that the new high-frequency PINPMN-PT thin film could be applied in a variety of fields because its performance has been verified.