Size Effects in Ferroelectric Nanocones

Abstract

In this work, we have performed for the first time a calculation of the ferroelectric size effect of cone-shaped nanoparticles (nanocones). To solve the appropriate Euler-Lagrange equations, a direct variational method was used. An approximate analytical expression for the phase transition temperature dependence on nanocone height and half-angle was derived. We have shown that the transition temperature may be higher by a factor of up to 2.5 compared to bulk materials.

Keywords:

• Nanoparticles
• nanocone
• depolarization field
• size effects
• phase digrams

PACS:

• 77.80.-e
• 77.22.Ej
• 78.67.Bf
• 77.80.Bh
• 77.84.Dy

Acknowledgments

This work was supported by the German Research Council (DFG) as part of the Research Group FOR 520 and by the grant UKR 05/001 (International Bureau of the German Federal Ministry of Education and Research).