Abstract
We have investigated ferroelectric (FE) and structural antiphase (SAP) domains and domain wall structures at the atomic scale in hexagonal YMn1-xTixO3-delta by using aberration-corrected high-angle annular-dark-field scanning transmission electron microscopy (HAADF-STEM) experiments, combining with the conventional TEM observation techniques. Atomic shifts of Y3+ and Mn3+ (Ti4+) in the FE and SAP domains and domain wall structures in YMn1-xTixO3-delta are successfully visualized at the atomic scale. When Ti4+ are substituted for Mn3+, the magnitude of the shifts of Y3+ is reduced and the regions without any displacement of Y3+ along the [001] direction dominated around x-0.40. Our experimental results clearly revealed that partial substitution of Ti4+ for Mn3+ suppress the magnitude of the shifts of Y3+ ions along the [001] direction and the FE properties tend to diminish with increasing the amount of Ti4+ in YMn1-xTixO3-delta.