In Situ Observation of Point‐Defect‐Induced Unit‐Cell‐Wise Energy Storage Pathway in Antiferroelectric PbZrO3

• Published in: Advanced functional materials 2021-03, Vol.31 (13), p.n/a
• Main Authors: Wei, Xian‐Kui, Jia, Chun‐Lin, Roleder, Krystian, Dunin‐Borkowski, Rafal E., Mayer, Joachim
• Format: Article
• Language: English
• Subjects: Antiferroelectricity; charged domain walls; Energy storage; ferrodistortive transition; in situ transmission electron microscopy; Materials science; PbZrO3; Phase transitions
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202008609

Phase transition is established to govern electrostatic energy storage for antiferroelectric (AFE)‐type dielectric capacitors. However, the source of inducing the phase transition and the pathway of storing the energy remains elusive so far given the ultrafast charging/discharging process under normal working conditions. Here, by slowing down the phase‐transition speed using electron‐beam irradiation as an external stimulus, the in situ dynamic energy‐storage process in AFE PbZrO3 is captured by using atomic‐resolution transmission electron microscopy. Specifically, it is found that oxygen‐lead‐vacancy‐induced defect core acts as a seed to initiate the antiferrodistortive‐to‐ferrodistortive transition in antiparallel‐Pb‐based structural frames. Associated with polarity evolution of the compressively strained defect core, the ferroelectric (FE)–ferrodistortive state expands bilaterally along the b‐axis direction and then develops into charged domain configurations during the energy‐storage process, which is further evidenced by observations at the ordinary FE states. With filling the gap of perception, the findings here provide a straightforward approach of unveiling the unit‐cell‐wise energy storage pathway in chemical defect‐engineered dielectric ceramics. In situ probing of the energy‐storage pathway provides a fundamental perspective to elaborate the structure–property relationship. Here, by slowing down the phase‐transition speed, the in situ atomic‐scale transmission electron microscopy study of antiferroelectric PbZrO3 reveals that, associated with the presence of charged domain walls, point defects may act as seeds to initiate unit‐cell‐wise structural phase transition and electrostatic energy storage.