A5 Ferroelectric Fatigue (Polarization Aging)

Topic

The degradation of the piezoelectric response—the phenomenon described by this model—begins when a material is subjected to repeated electrical cycling. This cycling causes the material's remanent polarization to degrade, following a logarithmic law.

This logarithmic degradation does not proceed at a constant rate; the initial cycles cause the greatest loss of remanent polarization. As the number of accumulated cycles increases, each additional cycle causes progressively less degradation of the remanent polarization—meaning the response changes in proportion to the number of cycles, rather than decreasing by a fixed amount in each one.

This pattern of remanent polarization degradation leads to a corresponding reduction in the material's piezoelectric coefficient; indeed, it is this reduction in the piezoelectric coefficient that constitutes, in practical terms, the degradation of the piezoelectric response with which this model began.

Thus, this model describes an aging anomaly within the general behavior of piezoelectricity and ferroelectricity: whereas that general behavior assumes stable remanent polarization, this model describes precisely what happens when repeated electrical cycling erodes that polarization over time, causing the piezoelectric response to erode along with it.

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