High-frequency and high-temperature electromechanical performances of new PZT-PNN piezoceramics

Ferroelectric ceramics based on a solid solution between a PZT ferroelectri c phase and a relaxor phase from the lead-nickel-niobium system are charact erised. Two different mixed-oxide routes have been used in order to compare the dielectric, piezoelectric and elastic properties of the two ceramics o btained. The characterisation method is based on measurements of the electr ical impedance of samples as a function of frequency and allows the determi nation of the thickness mode resonance parameters. Results are given as a f unction of frequency (5 to over 25 MHz) and temperature (ambient to over 23 0 degreesC). Finally, several simulations, using a K.L.M. model, of medical transducers are performed. The results show that the ceramic is well adapt ed for medical imaging applications, in particular for array transducer con figurations. (C) 2001 Elsevier Science Ltd. All rights reserved.