Nanoscale analysis of dispersive ferroelectric domains in bulk of hexagonal multiferroic ceramics

• Published in: Materials characterization Vol. 145; pp. 347 - 352
• Main Authors: Baghizadeh, Ali, Vieira, Joaquim M., Stroppa, Daniel G., Willinger, Marc-Georg, Amaral, Vitor S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2018
• Subjects: Aberration corrected STEM; CERAMICS; Defective lattices; DISTURBANCES; DOPED MATERIALS; EDGE DISLOCATIONS; ELECTRICAL PROPERTIES; Ferroelectric domains; FERROELECTRIC MATERIALS; LUTETIUM COMPOUNDS; MAGNETIC PROPERTIES; MANGANATES; MATERIALS SCIENCE; MODIFICATIONS; Multiferroic oxides; NANOSTRUCTURES; PERTURBATION THEORY; PHASE SHIFT; POLARIZATION; VACANCIES; Ferroelectric domains; Multiferroic oxides; Aberration corrected STEM; Defective lattices
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2018.08.042

The atomic nature of topologically protected ferroelectric (FE) walls in hexagonal ReMnO3 oxides (R: Sc, Y, Er, Ho, Yb, Lu) creates an interesting playground to study effects of defects on domain walls. The 6-fold FE vortices in this multiferroic family lose the ordering by the rule of 6 in the presence of partial edge dislocations (PED) besides it can be modified by chemical doping. Therefore, it is essential to comprehend the cross coupling of FE walls and defects or vacancies in the lattice of multiferroics. Atomic resolution STEM is used to explore the correlative response of electrical polarization of FE domains in the presence of defects in multiferroic ceramics. Such level of resolution also allows the study of switching of FE domains on encounter of lattice defects. The driving force behind appearance of dispersed, small FE domains in images of piezo force microscopy is revealed by observation of lattice defects and FE boundaries simultaneously at the nano-scale. Planar defects and FE domain walls play their role of internal interfaces consequently such interplaying duly modifies the magnetic and FE properties of multiferroic oxides. •Aberration corrected STEM is used to link ferroelectric properties of vacancy doped multiferroic LuMnO3 ceramics to lattice defects.•Nano-scale perturbation in lattice or chemistry provokes polarization switching or phase shift of ferroelectric domains.•Partial edge dislocations modify rule of 6 in topologically protected 6-fold vortices in hexagonal RMnO3 ceramics.•Chemistry shift/lattice distortions modify ferroelectric properties, domain size and polarization switching in multiferroic.•Change in ferroelectric properties results in modification of magnetic properties in magnetoelectric h-RMnO3 multiferroic.