Origin of horizontal strip features in KTa1−xNbxO3 crystals

Identify the origin and nature of the horizontal strip features observed in KTa0.7Nb0.3O3 crystals before mechanical deformation, determining whether they are structural defects associated with crystal growth and how they affect dislocation motion and yield stress.

Background

During bulk compression experiments on KTa0.7Nb0.3O3, the sample exhibited numerous horizontal strip features before deformation. The features persisted during subsequent deformation and were therefore interpreted as immobile and distinct from ferroelectric domains.

The paper suggests that these features are most likely structural defects introduced during crystal growth. Because such defects could impede dislocation motion and increase the yield stress, determining their precise identity and origin is important for interpreting the anomalously high strength of KTa0.7Nb0.3O3 and for improving the reproducibility of mechanical-property measurements in potassium tantalate niobate crystals.

References

It is unclear at this stage what these strips are, but given the fact that these strips persist during the following-up deformation process, they are immobile and not ferroelectric domains, but most likely some structural defects induced during the crystal growth, which remains a common challenge in growing KTNO crystals [33].

— A solid-solution approach for room-temperature bulk plasticity in KTa1-xNbxO3  (2608.26678 - Frisch et al., 27 Aug 2026) in Section 3, Results and Discussions, page 4