Coexistence of multi-scale domains in ferroelectric polycrystals with non-uniform grain-size distributions

TL;DR

This study reveals how non-uniform grain sizes in ferroelectric DyMnO3 polycrystals lead to the coexistence of multi-scale domains, offering new insights for domain engineering in complex microstructures.

Contribution

It demonstrates that non-uniform grain-size distributions induce multi-scale domain coexistence, expanding understanding of domain formation in ferroelectric polycrystals.

Findings

Multi-scale domains coexist due to non-uniform grain sizes.

Domain size varies by up to an order of magnitude.

Micrometer-sized grains act as individual ferroelectric units.

Abstract

Engineering of ferroelectric domain structures enables direct control over the switching dynamics and is crucial for tuning the functional properties of ferroelectrics for various applications, ranging from capacitors to future nanoelectronics. Here, we investigate domain formation in poly- and single crystalline improper ferroelectric DyMnO3. We show that a non-uniform grain-size distribution in the polycrystals facilitates the coexistence of multi-scale domains, varying by up to one order of magnitude in size. This unusual domain structure originates from an inverted domain-size/grain-size dependence that is intrinsic to the hexagonal manganite polycrystals, expanding previous studies towards non-uniform grain-size distributions. Our results demonstrate that the micrometer-sized grains in DyMnO3 represent individual ferroelectric units with a characteristic domain structure, giving a new dimension to domain engineering in ferroelectric polycrystals with non-uniform microstructures.