Topological phase transformations and intrinsic size effects in ferroelectric nanoparticles

Abstract

Composite materials comprised of ferroelectric nanoparticles in a dielectric matrix are being actively investigated for a variety of functional properties attractive for a wide range of novel electronic and energy harvesting devices. However, the dependence of these functionalities on shapes, sizes, orientation and mutual arrangement of ferroelectric particles is currently not fully understood. In this study, we utilize a time-dependent Ginzburg-Landau approach combined with coupled-physics finite-element-method based simulations to elucidate the behavior of polarization in isolated spherical PbTiO3 or BaTiO3 nanoparticles embedded in a dielectric medium, including air. The equilibrium polarization topology is strongly affected by particle diameter, as well as the choice of inclusion and matrix materials, with monodomain, vortex-like and multidomain patterns emerging for various combinations of size and materials parameters. This leads to radically different polarization vs electric field responses, resulting in highly tunable size-dependent dielectric properties that should be possible to observe experimentally. Our calculations show that there is a critical particle size below which ferroelectricity vanishes. For the PbTiO3 particle, this size is 2 and 3.4 nm, respectively, for high- and low-permittivity media. For the BaTiO3 particle, it is ~3.6 nm regardless of the medium dielectric strength.

References in corpus (6)

• A ferroelectric memristor
• Direct observation of the proliferation of ferroelectric loop domains and vortex-antivortex pairs
• Atomistic treatment of depolarizing energy and field in ferroelectric nanostructures
• Unusual polarization patterns in flat epitaxial ferroelectric nanoparticles
• Superparaelectric phase in the ensemble of non-interacting ferroelectric nanoparticles
• Multidomain switching in the ferroelectric nanodots

Cited by in corpus (13)

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• Revealing the Three-Dimensional Arrangement of Polar Topology in Nanoparticles
• Flexo-Elastic Control Factors of Domain Morphology in Core-Shell Ferroelectric Nanoparticles: Soft and Rigid Shells
• Electromechanical control of polarization vortex ordering in an interacting ferroelectric-dielectric composite dimer
• Domain alignment within ferroelectric/dielectric PbTiO${}_3$/SrTiO${}_3$ superlattice nanostructures
• Stress-Induced Transformations of Polarization Switching in CuInP${}_2$S${}_6$ Nanoparticles
• Ferroelectric texture of individual barium titanate nanocrystals
• Vortex states in a PbTiO${}_3$ ferroelectric cylinder
• Flash annealing-engineered wafer-scale relaxor antiferroelectrics for enhanced energy storage performance
• Reentrant polar phase induced by the ferro-ionic coupling in Bi${}_{1-x}$Sm${}_x$FeO${}_3$ nanoparticles
• A coupled magneto-structural continuum model for multiferroic ${\mathrm{BiFeO}}_3$