Title :
High-frequency ultrasonic transducer fabricated with lead-free piezoelectric single crystal
Author :
Chen, Yan ; Jiang, Xiang Ping ; Luo, Hao Su ; Dai, Ji Yan ; Chan, Helen L.W.
Author_Institution :
Dept. of Appl. Phys., Hong Kong Polytech. Univ., Hong Kong, China
fDate :
11/1/2010 12:00:00 AM
Abstract :
High-frequency (25 MHz) ultrasonic transducers with Na0.5Bi0.5TiO3-BaTiO3 (NBT-BT) lead-free piezoelectric single crystal as the active elements are fabricated and characterized. The impedance measurement reveals that the poled [001]-oriented NBT-BT single crystal exhibits a high thickness electromechanical coefficient kt of 0.52 and a low clamped dielectric constant of 80. The -6-dB bandwidth of the transducer is 46.16% and the insertion loss at the center frequency is -31.89 dB. The good performance of the transducer indicates that the NBT-BT single crystal would be a promising lead-free material for ultrasonic transducer applications.
Keywords :
barium compounds; bismuth compounds; dielectric losses; dielectric polarisation; electric impedance; permittivity; piezoelectric materials; piezoelectric transducers; piezoelectricity; sodium compounds; ultrasonic transducers; Na0.5Bi0.5TiO3-BaTiO3; clamped dielectric constant; frequency 25 MHz; high-frequency ultrasonic transducer; high-thickness electromechanical coefficient; impedance measurement; insertion loss; lead-free piezoelectric single crystal; poled [001]-oriented NBT-BT single crystal; ultrasonic transducer applications; Acoustics; Crystals; Frequency measurement; Transducers; Ultrasonic transducers;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2010.1727
