High-frequency PIN-PMN-PT single crystal ultrasonic transducer for imaging applications

摘要

A high-frequency (∼60 MHz) ultrasonic transducer with a [001]-oriented 0.27Pb(In 1/2Nb 1/2)O 3-0.45Pb(Mg 1/3Nb 2/3)O 3-0.28PbTiO 3 (PIN-PMN-PT) piezoelectric single crystal as an active element has been fabricated and characterized. The poled PIN-PMN-PT single crystal has thickness mode electromechanical coefficient k t of 0.56 and piezoelectric constant d 33 of 1550 pC/N. The -6 dB bandwidth of the transducer is 73 % and the insertion loss at its centre frequency is -20 dB. With the study as a function of temperature, the PIN-PMN-PT transducer shows better thermal stability than the binary single crystal transducer. Furthermore, the transducer was evaluated using a 30-μm aluminum wire phantom image, in which the -6 dB axial and lateral resolutions are found to be 26 μm and 127 μm, respectively. Ultrasonic images of fish eyes were obtained with the 60-MHz transducer. It is shown that the high-sensitivity transducer can produce the images with high signal-to-noise ratio and good contrast.