Electroelastic effect of thickness mode langasite resonators

Area of Science:

• Materials Science
• Solid State Physics
• Electrical Engineering

Background:

• Langasite (LGS) is a promising piezoelectric material for resonators, offering excellent temperature stability, high piezoelectric coupling, low acoustic loss, and high Q factor.
• Understanding the biasing effect, particularly the resonant frequency shift under an applied direct current (DC) electric field, is critical for optimizing langasite resonator design.

Purpose of the Study:

• To analyze the resonant frequency shift in thickness-mode langasite resonators subjected to a DC electric field applied in the thickness direction.
• To investigate the electroelastic effect in langasite resonators using both analytical and numerical approaches.

Main Methods:

• The study employs the theory for small fields superposed on a bias in electroelastic bodies and the first-order perturbation integral theory.
• Vibration modes of a thin langasite plate with full electrode coverage are analyzed.
• Both analytical and finite-element methods are utilized to examine the electroelastic effect.

Main Results:

• The resonant frequency shift of thickness-mode langasite resonators under DC electric field biasing is quantified.
• The analysis incorporates the complete set of nonlinear elastic, piezoelectric, dielectric permeability, and electrostrictive constants of langasite.
• The sensitivity of the electroelastic effect to these nonlinear material constants is systematically evaluated.

Conclusions:

• The biasing effect significantly influences the resonant frequency of langasite resonators.
• The comprehensive analysis provides valuable insights for the precise design and application of langasite-based resonators.
• Accurate material constants are essential for predicting and controlling the electroelastic behavior of langasite resonators.