Single-crystal relaxor ferroelectric piezoactuators with interdigitated electrodes.

Area of Science:

• Materials Science
• Solid State Physics
• Crystallography

Background:

• Lead zinc niobate-lead titanate (PZN-PT) single crystals are known for their excellent piezoelectric properties.
• Relaxor ferroelectrics offer unique electromechanical responses.
• Actuation mechanisms in single-crystal piezoelectrics are crucial for device development.

Purpose of the Study:

• To fabricate and characterize (1-x) Pb(Zn(1/3)Nb(2/3))O3-xPbTiO3 (PZN-PT) single-crystal relaxor piezoactuators.
• To investigate actuation induced by an electric field gradient across the sample thickness.
• To compare experimental piezoelectric response with theoretical predictions.

Main Methods:

• Fabrication of PZN-PT single crystals.
• Patterning of interdigitated electrodes on a single crystal surface.
• Poling of samples at 100°C under an applied electric field.
• Measurement of piezoelectric response under electric field gradient.

Main Results:

• Successful fabrication of PZN-PT single-crystal piezoactuators.
• Actuation achieved through an electric field gradient, causing differential contraction.
• Experimental piezoelectric response showed good agreement with calculations based on a modulated dipolar field model.
• Discrepancies attributed to multidomain formation due to electric field reversals.

Conclusions:

• The study demonstrates a viable method for fabricating PZN-PT single-crystal piezoactuators.
• Electric field gradients effectively induce actuation in these materials.
• The developed model provides a good approximation of the piezoelectric response, with deviations highlighting complex domain behavior.