Size and shape effects on polarization reversal of nanoscale BaTiO₃

Abstract

We report piezo force microscopy (PFM) investigations on the ferroelectric switching characteristics of spherical and rod shaped non-interacting nanocrystalline BaTiO₃ (BTO). Polarization-voltage hysteresis loop (P-E hysteresis loop) measurement shows that the strong polarization reversal observed for the nanorod (NR) shaped BTO than the spherical nanoparticle (NP). Asymmetric P-E loop is observed for all kind of BTO NRs. From the PFM spectroscopy and ferroelectric switching studies reveal that the defect dipoles present in the BTO NR at below 60 nm have no significant effect on the asymmetric P-E hysteresis loop. It is strongly depends on the strain between the substrate and BTO NRs.

Keywords:

• Nanoscale BaTiO₃
• size effect
• imprint
• polarization switching and piezo force microscopy

Acknowledgments

The authors R.M. and A.R. acknowledge the Indira Gandhi Centre for Atomic Research, India, for support AFM measurement.