Structure and defect characterization of multiferroic ReMnO(3) films and multilayers by TEM

Area of Science:

• Materials Science
• Solid State Physics
• Thin Film Technology

Background:

• Rare earth manganite (ReMnO3) thin films and multilayers are crucial for advanced electronic applications.
• Controlling epitaxial growth and understanding defect formation are key challenges in ReMnO3 thin film fabrication.

Purpose of the Study:

• To investigate the structural properties of epitaxial ReMnO3 thin films and multilayers grown on different substrates.
• To analyze the influence of substrate misorientation, film thickness, and substrate type on defect formation.
• To propose and verify atomic growth models for the film/substrate interface.

Main Methods:

• Liquid injection metal organic chemical vapor deposition (MOCVD) for film and multilayer growth.
• Electron diffraction (ED) and high-resolution transmission electron microscopy (HRTEM) for structural characterization.
• Computer simulations to verify atomic growth models.

Main Results:

• Observed nanodomains of secondary orientation in hexagonal YMnO3 films, linked to substrate misorientation.
• Identified TbO2 and Er2O3 inclusions in TbMnO3 and ErMnO3 films, respectively, with structures related to film and substrate symmetry.
• Demonstrated that substrate type influences defect formation in YMnO3/HoMnO3 and YMnO3/ErMnO3 multilayers.

Conclusions:

• Epitaxial growth of ReMnO3 films is sensitive to substrate properties and deposition conditions.
• Atomic growth models provide insights into the interface structure and defect mechanisms.
• Understanding these relationships is vital for optimizing ReMnO3 thin films for technological applications.