3.2.4 Memory Wipe Out

An interesting feature of ferroelectric or ferromagnetic materials is the effect of memory wipe out. This effect occurs if the amplitude of the electric field is increased again after several depolarization cycles have been performed. This is sketched in Fig. 3.13. Starting from negative saturation two subcycles with decreasing amplitude are applied until the operating point D is reached. As outlined in the previous subsection, the local subloop of the hysteresis has to hit the last turning point C. If the electric field still increases and finally gets higher than the last local maximum $E_C$, which is shown in the PE-diagram in Fig. 3.9, the PE-diagram will transform into the form outlined in Fig. 3.5. This is identical to the situation before the last subcycle CDC was applied to the material. This means that this subcycle has no influence on the future behavior of the material, so the hysteresis will proceed to operating point A, and, if the field is further increased, along the saturation loop.

Figure 3.13: Memory wipe out