Unlocking Electrostrain in Plastically Deformed Barium Titanate

Area of Science:

• Materials Science
• Solid State Physics
• Crystallography

Background:

• Achieving high electrostrain and piezoelectric coefficients is crucial for advanced actuator applications.
• Current piezoelectric materials face limitations in performance and often contain lead.

Purpose of the Study:

• To enhance electrostrain and piezoelectric properties in single-crystal barium titanate through dislocation engineering.
• To investigate the impact of ordered dislocations on domain structure and switching behavior.

Main Methods:

• Introduction of ordered {100}<100> dislocations into single-crystal BaTiO3.
• Characterization using optical microscopy, transmission electron microscopy, and X-ray diffraction (laboratory and synchrotron).
• Phase-field simulations to understand dislocation effects on domain dynamics.

Main Results:

• Engineered BaTiO3 exhibited an intrinsic electrostrain of 0.69% at 10 kV cm⁻¹.
• Achieved strain energy density of 5.24 J cm⁻³ without external stress.
• Electrostrains exceeding 1% and a d33* over 10,000 pm V⁻¹ were realized under 6 MPa compression.
• Record-high strain energy density of 11.67 J cm⁻³ was obtained.

Conclusions:

• Dislocation engineering provides an effective strategy for enhancing piezoelectric performance in lead-free materials.
• The developed approach offers a sustainable route for high-performance piezoelectric actuators.
• This method demonstrates significant potential for next-generation actuator technologies.