Landau theory of ferroelectric transition in long cylindrical nanoparticles
Department of Physics, Banaras Hindu University, Varanasi, 221005, India
Corresponding author: a email@example.com
Revised: 8 April 2008
Published online: 20 June 2008
Using a phenomenological Landau theory, the size dependence on ferroelectric transition for free-standing long cylindrical nanoparticles is discussed. We derive the size dependence of the transition temperature, polarization profile as well as the static susceptibility. The transition temperature vanishes below a critical size where the static susceptibility shows divergence obeying Curie-Weiss law. In order to make this result compared with experiments, the average polarization and the susceptibility is computed with a Gaussian particle size distribution. The average polarization in such a case shows smearing with respect to the particle size whereas the divergence in the susceptibilty gets rounded. This might correspond to a size dependent soft mode which can be observed in Raman measurement.
PACS: 64.70.Nd – Structural transitions in nanoscale materials / 77.80.-e – Ferroelectricity and antiferroelectricity / 77.84.Dy – Niobates, titanates, tantalates, PZT ceramics, etc.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008