Switching Behaviours of Ferroelectric Systems of Finite Size

Abstract

We present a study on switching behaviours of ferroelectric systems of finite size based on the discrete form of Landau-Devonshire free energy expression for different conditions of polarization at the edges that relate to the values of the extrapolation length δ. As the system size increases, the delay in switching at the centre relative to switching near the edges is more remarkable for systems of zero or small polarization at the edges (δ ≅ 0). It is found that the dipole moments at the centre and near the edges switch almost together in small-sized systems of any magnitudes of δ. The results show that the extrapolation length δ affects the coercive field.

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 of Malaysia (Grant No: 304/PFIZIK/653018/A118). We are thankful to Prof. Yoshihiro Ishibashi for his kind opinions about this work.