Grain Plastic Rearrangement for Fabricating Textured CaBi₂Nb₂O₉-Based Ceramics with Superior Piezoelectricity

Area of Science:

• Materials Science
• Solid State Physics
• Ceramics Engineering

Background:

• Bismuth layer-structured ferroelectrics (BLSFs) are crucial for high-temperature piezoelectric applications due to their high Curie temperature and fatigue resistance.
• However, BLSFs traditionally suffer from suboptimal piezoelectric properties, limiting their performance.
• Theoretical studies suggest [100]-oriented CaBi2N2O9 (CBN) ceramics can significantly enhance piezoelectric coefficients (d33).

Purpose of the Study:

• To develop a novel, template-free method for fabricating [100]-oriented textured CBN-based ceramics.
• To investigate the impact of this texturing on the piezoelectric properties of BLSFs.
• To assess the thermal stability of the enhanced piezoelectric performance.

Main Methods:

• A seed-free hot forging technique was employed, utilizing grain plastic rearrangement at elevated temperatures.
• The method avoids the need for pre-existing grain templates, simplifying the process.
• Characterization of the textured ceramics included measurement of piezoelectric coefficients (d33) and thermal stability tests.

Main Results:

• The seed-free hot forging technique successfully produced [100]-oriented textured CBN-based ceramics.
• A superior d33 of 26.7 pC/N was achieved, representing a 53% improvement over standard ceramics.
• The textured ceramics maintained excellent piezoelectric performance, with d33 remaining at 25.7 pC/N after annealing at 900 °C.

Conclusions:

• The seed-free hot forging technique offers a simpler, cost-effective approach to producing high-performance textured BLSF ceramics.
• This method significantly enhances piezoelectric properties, particularly d33, making BLSFs more viable for demanding high-temperature applications.
• The developed technique shows broad potential for application across various BLSF materials.