Bimodal domain configuration and wedge formation in tetragonal Pb[Zr1−xTix]O3 ferroelectrics

• By transmission electron microscopy a bimodal domain structure is discovered.
• The observed domain structure contains charged domain walls.
• Phase field simulations were used to study formation of this bimodal structure.
• Bimodal structure can be induced by charges and/or shear loading on the boundary.
• Charge density influences the aspect ratio of the bimodal domain structure.

In this study, the domain structure, bimodality of domains and wedge-shape formation of domain tips are investigated in tetragonal Pb[Zr0.375Ti0.625]O3 and Pb[Zr0.45Ti0.55]O3 ferroelectrics by transmission electron microscopy (TEM). Finite element method (FEM) calculations predicted the stability of the experimentally observed domain configuration for different boundary conditions concerning electrical as well as mechanical state. Detailed TEM studies of a specific bimodal domain configuration, composed of four different domains, revealed the presence of a domain wall with alternating tiny head-to-side and tail-to-side arrays and broad head-to-tail areas. The experimentally observed existence of both, wedge-shaped domain tips and bimodality, could be rationalized either by the presence of charges or by shear stress as evidenced by FEM calculations.