Microcracking and discontinuous fast switching as acoustic emission sources in 8/65/35 and 9.5/65/35 PLZT relaxor ferroelectrics

Evaluation of Ferroelectric Domain Behaviors Using Acoustic Emission Method

“…As the strain induced from 2.0 to 2.5 kV/mm in the second cycle is identical to that obtained in the following cycle, the 180 domain reorientation may be related to these AE activities. However, since electric-field-induced AE activities have also been also reported for electrostrictive ceramics 8,9) in which the ferroelectric domains do not exist, these AE activities, including those during the poling process, cannot be attributed to only the type of domain reorientation (i.e., 180 domain reorientation or non-180 (90 ) domain reorientation). Although the stress reduction at the grain boundaries can also be the origin of AE, it is apparent that the energy loss mechanisms of strain induction are dependent on structural changes of the ferroelectric domains.…”

“…The acoustic emission (AE) method is a nondestructive technique used to detect acoustic pulses of released elastic strain energy caused by deformation, crack growth, and phase changes in materials. 1) For ferroelectric materials, the AE method has been used to detect domain reorientation, [2][3][4][5][6][7][8][9] phase transitions, [10][11][12] and to monitor crack propagation and material fatigue. [13][14][15][16][17][18][19] However, in the electric-field-induced AE measurements of ferroelectric/piezoelectric materials, there are two kinds of AE signals: AE signals from within the sample and vibroacoustic emission (vibro-AE) signals related to the piezoelectricity of the sample.…”

Electric field-induced transformations in bismuth sodium titanate-based materials

“…for ferroelectrics [265][266][267], relaxors [268] and antiferroelectrics [269]. For non-fatigued and non-aged ferroelectrics, acoustic emissions are usually recorded near or above the coercive field, and can have different possible origins [265,267,270,271] sequence and showed some differences depending on the grain size [269].…”