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Lecture

WEB Revealing domain configurations of a novel NaNbO3 based solid solution by transmission electron microscopy

Tuesday (22.09.2020)
16:10 - 16:25 C: Characterization 1
Part of:


Antiferroelectric (AFE) materials have potential applications in a wide range of areas, e.g., large-strain actuators, electrocaloric refrigeration and high-energy storage capacitors. A novel antiferroelectric material with composition (1-x)NaNbO3-xSrSnO3 solid solution has been recently established with a characteristic double hysteresis loop at room temperature. Namely, the incorporation of SrSnO3 stabilizes the antiferroelectric state against the ferroelectric state in the NaNbO3 upon the application of external electric field. Understanding the microstructure evolution by chemical modification is fundamental towards gaining an insight into the physical properties, and thus establishing structure-property correlations. In this contribution, a transmission electron microscopy (TEM) study has been carried out to investigate the crystallography and domain configuration of this novel system, by approaches of electron diffraction and centered dark field imaging.  It was found out that the antiferroelectricity is maintained at all compositions, manifested by the characteristic ¼ superlattice reflections in the electron diffraction patterns. When 5% SrSnO3 is introduced into the system, the material demonstrates a very defined and distinct domain structure and sharp domain boundaries, corresponding to the pronounced double hysteresis loop with significant decrease of the remanent polarization compared to pure NaNbO3. This study further aims towards obtaining a direct observation of the domain configuration evolution of pure NaNbO3 when in-situ biasing in TEM is applied together with 4D STEM to allow a detailed understanding of the field-induced phase transition

Speaker:
Hui Ding
Technische Universität Darmstadt
Additional Authors:
  • Mao-Hua Zhang
    TU Darmstadt
  • Dr. Jurij Koruza
    TU Darmstadt
  • Prof. Hans-Joachim Kleebe
    TU Darmstadt
  • Prof. Leopoldo Molina-Luna
    TU Darmstadt