Effects of quenching on domain switching and electric field-induced phase transformations in Na0.5Bi0.5TiO3-NaNbO3 ceramics

• Published in: Journal of the European Ceramic Society Vol. 44; no. 15; p. 116767
• Main Authors: Pan, Juncheng, Li, Yizhe, Yang, Ziqi, Xie, Bingying, Shi, Jiajun, Hall, David A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2024
• Subjects: Domain orientation distribution; Phase switching; Relaxor ferroelectric; Sodium bismuth titanate; X-ray diffraction; X-ray diffraction; Relaxor ferroelectric; Phase switching; Sodium bismuth titanate; Domain orientation distribution
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2024.116767

Quenching from high temperatures has been identified as a useful means to enhance the piezoelectric properties and thermal stability of bismuth-based perovskite ferroelectrics. In the present work, it is demonstrated that quenching leads to improvement of depolarization temperature, ferroelectric and piezoelectric properties in Na0.5Bi0.5TiO3-NaNbO3 (NBT-0.1NN) ceramics. In-situ synchrotron x-ray diffraction measurements indicated an irreversible transformation from cubic to coexisting cubic and rhombohedral phases during the application of a high electric field, for both as-sintered and quenched ceramics. These results confirm the non-ergodic relaxor ferroelectric nature of the materials. DC poling induced a transformation to single-phase rhombohedral structure in both cases, with highly textured domain configurations. These well-oriented ferroelectric domain states were relatively stable under subsequent bipolar electric field cycling. For the pre-poled NBT-0.1NN ceramics, the quenched samples were found to exhibit the highest intrinsic (lattice strain) and extrinsic (domain switching) contributions to electrostrain, due to the increased rhombohedral distortion. •High energy x-ray diffraction is used to analyse the structure of NBT-NN ceramics.•Coexisting cubic and rhombohedral phases are induced by an applied electric field.•Quenched samples have more rhombohedral phase and enhanced ferroelectricity.•DC poling results in transformation to a highly textured single rhombohedral phase.•Electrostrain is dominated by the intrinsic lattice strain mechanism.