Giant linear strain gradient with extremely low elastic energy in a perovskite nanostructure array

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Inhomogeneous elastic strains can modify nanoscale functional materials.
• Developing devices dominated by inhomogeneous strains remains a challenge.

Purpose of the Study:

• To fabricate inhomogeneous strains with a linear gradient.
• To investigate the properties and potential applications of these strained nanostructures.

Main Methods:

• Growing arrays of BiFeO3 nanostructures on LaAlO3 substrates using a high deposition flux.
• Inducing linear strain gradients as large as 10^6 per meter.

Main Results:

• Achieved significantly lower elastic energy cost compared to uniform strain.
• Induced polarization of several microcoulomb per square centimeter.
• Generated a built-in electric field of several megavoltage per meter.
• Observed a large enhancement in solar absorption.

Conclusions:

• Demonstrated the feasibility of creating large-scale, strain-dominated nanostructures.
• These nanostructures exhibit exotic properties with potential for novel electromechanical and photoelectric devices.