Title :
Effect of dielectric relaxation on the performance of P(VDF-TrFE) copolymer ultrasonic transducers
Author :
Kwok, K.W. ; Chan, H.L.W. ; Choy, C.L.
Author_Institution :
Dept. of Appl. Phys., Hong Kong Polytech. Univ., Kowloon, Hong Kong
Abstract :
The complex dielectric permittivity of vinylidene fluoride-trifluoroethylene copolymer with 20 mol% of TrFE [P(VDF-TrFE) 80/20] has been measured over the frequency range of 500 kHz to 20 MHz at temperatures varying from 20° to 100°C. This copolymer has the highest electromechanical coupling coefficient kt among all TrFE compositions and has thus attracted considerable interest in ultrasonic transducer applications. The effect of dielectric relaxation on the performance of VDF-TrFE transducers is discussed
Keywords :
dielectric relaxation; permittivity; piezoelectric transducers; polymer blends; ultrasonic transducers; 20 to 100 C; 500 kHz to 20 MHz; P(VDF-TrFE); dielectric relaxation; electromechanical coupling coefficient; permittivity; ultrasonic transducer; vinylidene fluoride-trifluoroethylene copolymer; Annealing; Dielectric losses; Dielectric materials; Dielectric measurements; Frequency; Impedance; Permittivity measurement; Resonance; Temperature distribution; Ultrasonic transducers;
Conference_Titel :
Applications of Ferroelectrics, 1998. ISAF 98. Proceedings of the Eleventh IEEE International Symposium on
Conference_Location :
Montreux
Print_ISBN :
0-7803-4959-8
DOI :
10.1109/ISAF.1998.786679
