Acoustic emission study of domain wall motion and phase transition in (1-x-y)Bi0.5Na0.5TiO3-xBaTiO3-yK0.5Na0.5NbO3 lead-free piezoceramics

The ferroelectric strain hysteresis and acoustic emissions of lead-free (1 - x - y)Bi0.5Na0.5TiO3-xBaTiO(3)-yK(0.5)Na(0.5)NbO(3) ceramics were investigated at room temperature. The field-induced antiferroelectric <-> ferroelectric phase transition as well as the ferroelectric coercive field were successfully detected. Although the strain was largest for x = 0.06 and y = 0.02. this composition showed the lowest acoustic emission signals, making it an interesting material ultrasonic transducer applications. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.