Anisotropic dislocation-domain wall interactions in ferroelectrics

• Published in: Nature communications 2022-11, Vol.13 (1), p.6676-6676, Article 6676
• Main Authors: Zhuo, Fangping, Zhou, Xiandong, Gao, Shuang, Höfling, Marion, Dietrich, Felix, Groszewicz, Pedro B., Fulanović, Lovro, Breckner, Patrick, Wohninsland, Andreas, Xu, Bai-Xiang, Kleebe, Hans-Joachim, Tan, Xiaoli, Koruza, Jurij, Damjanovic, Dragan, Rödel, Jürgen
• Format: Article
• Language: English
• Subjects: 140/131; 147/143; 639/166/988; 639/301/1034; 639/301/119/996; Anisotropy; Barium; Barium titanates; Crystal defects; Crystals; Degradation; Dislocation; Domain walls; Ferroelectric materials; Ferroelectricity; Ferroelectrics; Functional materials; Humanities and Social Sciences; Material properties; Materials science; Mechanical properties; multidisciplinary; NMR; Nuclear magnetic resonance; Optical properties; Piezoelectricity; Point defects; Science; Science (multidisciplinary); Single crystals; Transmission electron microscopy; X-ray diffraction
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-34304-7

Dislocations are usually expected to degrade electrical, thermal and optical functionality and to tune mechanical properties of materials. Here, we demonstrate a general framework for the control of dislocation–domain wall interactions in ferroics, employing an imprinted dislocation network. Anisotropic dielectric and electromechanical properties are engineered in barium titanate crystals via well-controlled line-plane relationships, culminating in extraordinary and stable large-signal dielectric permittivity (≈23100) and piezoelectric coefficient (≈2470 pm V –1 ). In contrast, a related increase in properties utilizing point-plane relation prompts a dramatic cyclic degradation. Observed dielectric and piezoelectric properties are rationalized using transmission electron microscopy and time- and cycle-dependent nuclear magnetic resonance paired with X-ray diffraction. Succinct mechanistic understanding is provided by phase-field simulations and driving force calculations of the described dislocation–domain wall interactions. Our 1D-2D defect approach offers a fertile ground for tailoring functionality in a wide range of functional material systems. Dislocations are often perceived as a culprit for degradation in functionality. Here, the authors introduce a general framework for engineering dislocations and domain walls and demonstrate its full potential on a ferroelectric BaTiO 3 single crystal.