Tilley-Zeks Model in Switching Phenomena of Ferroelectric Films

Abstract

We use the Tilley-Zeks model of Landau Devonshire free energy and the Landau Khalatnikov equation of motion to elucidate the phenomena of polarization reversal of second-order ferroelectric films, particularly the characteristics of hysteresis loops by the applied field and the response of bipolar pulses by the films. It is shown that at constant temperature, the size of hysteresis loops increases with increasing film thickness for + δ and the reverse is true for –δ. For a film of fixed thickness, the size of hysteresis loop decreases with increasing temperature for both cases of +δ and –δ. The model has also demonstrated the effects of magnitude and frequency of the applied field on the hysteresis loops are similar to the experimental results.

Keywords:

• Landau theory
• polarization reversal
• surface effect
• size effect

PACS numbers:

• 77.80.Fm
• 78.20Bh

Acknowledgments

The work is funded by the SAGA grant, Academy of Sciences Malaysia (Grant No: 304/PFIZIK/653018/A118). We thank Prof. David R. Tilley & Dr. Junaidah Osman for their helpful discussion.