Preisach hysteresis allows the simulation of the well-known effect of
depolarization: If the response of a triangularly shaped signal with
constantly decreasing amplitude as it is applied for depolarization of
ferroelectric materials is calculated, the scheme outlined above has
to be followed. It is assumed that the electric field is reduced to an
operating point and then increased again to the next operating
point
. The according Preisach-Everett diagram is plotted in
Fig. 3.9.
It is obvious that the dipoles that are already in the up direction (light red color) do not have to change their state. If the row of turning points with decreasing amplitude is extended, a distribution with the size of the up and down areas fairly equivalent, as outlined in Fig. 3.10, will evolve.
Consequently, the resulting polarization will be almost zero at zero applied field, thus reproducing a well-known physical fact. The hysteresis curve which documents the depolarization process is plotted in Fig. 3.11.