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

Volume

57

Issue

11

fYear

2010

fDate

11/1/2010 12:00:00 AM

Firstpage

2601

Lastpage

2604

Abstract

High-frequency (25 MHz) ultrasonic transducers with Na_0.5Bi_0.5TiO₃-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 k_t 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; Na_0.5Bi_0.5TiO₃-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;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/TUFFC.2010.1727

Filename

5611708