Ferroelectrics play an important role in today’s modern life. A large variety of applications including piezoelectric actuators, sensors, dielectric capacitors, memory devices, etc. are based on these materials. Recently, scientific interest has been given to the Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 (BZT-xBCT) perovskite ferroelectric, that exhibits superior electrical and mechanical properties. It is known that domain morphology plays a significant role in electromechanical properties of ferroelectrics. As the external electric field induces domain wall motion or domain switching, it is important to perform direct observations of domain structure evolution under electric field.
In the present study in situ transmission electron microscopy (TEM) was employed to reveal the evolution of ferroelectric domains under electric field and temperature in BZT-xBCT. It is shown that in situ TEM is an extremely powerful tool in order to visualize the real-time microstructural evolution in these materials. During the in situ electric field TEM experiments, a multiple-domain state (A) → nanodomain state → single-domain state transformation occurred during the poling process. With further increase in the applied field a multiple-domain state (B) appeared. This state could be associated with strain incompatibility between neighbouring grains under the electric field. The displacement of the domain walls and changes in the domain configuration during electrical poling indicated a high extrinsic contribution to the piezoelectric response in lead-free BZT – xBCT. The temperature induced ferroelectric → paraelectric phase transition in the BZT – xBCT is also investigated. On heating and cooling a microstructure evolution in BZT – xBCT system was observed. Irregular domains with curved walls appeared in BZT – xBCT due to internal stresses associated with coexistence of rhombohedral and tetragonal domains within one grain.
Figures:
In situ TEM bright field images of the BZT – 0.48BCT at (a) virgin state, (b) 0.5 kV/cm, (c) 1 kV/cm, (d) zero field. The direction of the poling field is indicated by bright arrows
To cite this abstract:
Marina Zakhozheva, Ljubomira Ana Schmitt, Yevheniy Pivak, Matias Acosta, Kun Zuo, Qiang Xu, Hans-Joachim Kleebe; The value of in situ transmission electron microscopy in studding ferroelectric materials.. The 16th European Microscopy Congress, Lyon, France. https://emc-proceedings.com/abstract/the-value-of-in-situ-transmission-electron-microscopy-in-studding-ferroelectric-materials/. Accessed: September 21, 2023« Back to The 16th European Microscopy Congress 2016
EMC Abstracts - https://emc-proceedings.com/abstract/the-value-of-in-situ-transmission-electron-microscopy-in-studding-ferroelectric-materials/