Ferroelectric and Structural Antiphase Domain and Domain Wall Structures in Y(Mn,Ti)O₃

Abstract

We have investigated ferroelectric (FE) and structural antiphase (SAP) domains and domain wall structures at the atomic scale in hexagonal YMn_1-xTi_xO_3-δ 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 YMn_1-xTi_xO_3-δ 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 YMn_1-xTi_xO_3-δ.

Keywords:

• Multiferroics
• hexagonal manganite
• STEM-HAADF
• domain structure