Re-use of this resource is governed by a Creative Commons Attribution-
Noncommercial-Share Alike 2.0 Licence UK: England & Wales
https://creativecommons.org/licenses/by-nc-sa/2.0/uk/
creative commons DoITPoMS logo
Depolarisation methods
P T
Thermal depoling
Near the Curie point, the net polarisation disappears, as the dipole moments unalign.
Electrical depoling
When an alternating electric field is placed over a piezoelectric to generate ultrasound, the reversed field depolarises the piezoelectric, given a strong enough field.
Mechanical depoling
A small stress, when applied to the piezoelectric, causes it to develop a charge, as seen previously. However, if the stress applied is too great, the atomic positions are completely changed, the dipole moments unalign, and the polarisation disappears.