Asymmetric Ferroelectric Flux-Non-Closure Domain Enabling Giant Polarizations Through Local Lattice-Defect-Induced...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Ferroelectric materials exhibit complex polar topologies, particularly in nanoscale superlattices.
• These topological domains arise from the interplay of collective polarization and mechanical boundary conditions like interfacial strain.
• Conventional ceramics and polycrystalline films often lack these polar topologies, especially when high polarization is desired.

Purpose of the Study:

• To demonstrate the formation of a new ferroelectric topological domain in polycrystalline Bismuth Ferrite (BiFeO3).
• To investigate the role of local lattice defects in inducing and modulating these topological domains.
• To achieve significantly enhanced ferroelectric polarizations in polycrystalline materials.

Main Methods:

• Utilized polycrystalline BiFeO3 as a prototype material.
• Investigated the formation of polarization-asymmetric flux-non-closure domains.
• Analyzed the influence of local lattice defects and induced antiphase boundaries.
• Characterized B-site Fe displacements and FeO6 rotation angles.

Main Results:

• Successfully formed polarization-asymmetric flux-non-closure domains (vortex-like) in polycrystalline BiFeO3.
• Local lattice defects induced antiphase boundaries, relaxing lattice strains and structural distortions.
• Observed significantly increased B-site Fe displacements and FeO6 rotation angles.
• Achieved greatly enhanced ferroelectric polarizations up to 165.6 µC cm⁻² due to abundant asymmetric domains.

Conclusions:

• The study presents a new ferroelectric topological domain in polycrystalline BiFeO3.
• Lattice defect engineering offers a pathway to control ferroelectric flux-non-closure patterns.
• This work provides a platform for optimizing ferroelectric properties and exploring novel topological states in polycrystalline materials.