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A strain-driven morphotropic phase boundary in BiFeO3
R J Zeches1, M D Rossell, J X Zhang
1Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA. rzeches@berkeley.edu
Science (New York, N.Y.)
|December 8, 2009
Summary
Researchers developed a new lead-free piezoelectric material, bismuth ferrite, by creating a morphotropic phase boundary. This material can switch between phases, showing potential for data storage and actuator applications.
Area of Science:
- Materials Science
- Solid State Physics
- Nanotechnology
Background:
- Piezoelectric materials convert mechanical to electrical energy.
- A morphotropic phase boundary is key for high electromechanical coupling.
- There is a need for lead-free piezoelectric alternatives.
Purpose of the Study:
- To engineer a lead-free piezoelectric material using bismuth ferrite.
- To create a morphotropic phase boundary in bismuth ferrite films.
- To explore its potential for device applications.
Main Methods:
- Epitaxial growth techniques were employed.
- Theoretical approaches were used in conjunction with experiments.
- Electric field-dependent studies were conducted.
Main Results:
- A morphotropic phase boundary was successfully formed in lead-free bismuth ferrite films via epitaxial constraint.
- Reversible switching between tetragonal-like and rhombohedral-like phases was observed.
- Measurable surface displacements occurred during phase switching.
Conclusions:
- Epitaxial constraint enables morphotropic phase boundary formation in bismuth ferrite.
- This lead-free piezoelectric system is promising for probe-based data storage.
- Potential applications include advanced actuator technologies.
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