Controllable Ferroelastic Switching in Epitaxial Self-Assembled Aurivillius Nanobricks

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Layered perovskites with Aurivillius phase exhibit high ferroelectric Curie temperatures and desirable environmental characteristics.
• Bismuth tungstate (Bi₂WO₆) is a simple Aurivillius phase material with notable ferroelastic and photo-electrochemical properties.
• Controlling the self-assembly and ferroelastic switching of Bi₂WO₆ nanoarchitectures is key for nanoscale applications.

Purpose of the Study:

• To epitaxially grow Bi₂WO₆ nanobrick arrays in a self-assembled manner.
• To enable perpendicular voltage manipulation of ferroelectric polarization vectors within these nanostructures.
• To explore ferroelectric/elastic engineering opportunities in Bi₂WO₆ for advanced applications.

Main Methods:

• Epitaxial growth of Bi₂WO₆ nanobrick arrays.
• Self-assembly fabrication techniques.
• Scanning probe microscopy and transmission electron microscopy for characterization.

Main Results:

• Successfully fabricated self-assembled Bi₂WO₆ nanobrick arrays with controlled orthorhombic orientation.
• Demonstrated nanoscale topology supporting both out-of-plane and in-plane ferroelectric polarization vectors.
• Quantified in-plane polarization vectors (78.6° and 101.4°) relative to substrate crystallographic axes.

Conclusions:

• This work establishes a pathway for perpendicular voltage control of ferroelectric polarization in Bi₂WO₆ nanostructures.
• The findings open new possibilities for ferroelectric/elastic engineering in Bi₂WO₆.
• Potential applications include advanced sensing, actuation, and catalysis.