Numerical Design and Optimization of High Performance Langasite and Hetero-Acoustic Layer-Based Surface Acoustic Wave...

Area of Science:

• Materials Science
• Acoustics
• Sensor Technology

Background:

• Langasite (La3Ga5SiO14, LGS)-based surface acoustic wave (SAW) devices are crucial for high-temperature industrial health monitoring.
• Conventional LGS SAW structures suffer from low quality factor (Q) due to spurious resonant peaks, limiting their performance.

Purpose of the Study:

• To propose and optimize a hetero-acoustic layer (HAL)-based structure for LGS SAW devices.
• To simultaneously achieve a high figure of merit (FOM) and high-temperature resistance.
• To enhance the Q factor and FOM of LGS-based SAW devices for improved sensor applications.

Main Methods:

• Utilized finite element method (FEM) and coupling-of-model (COM) combined simulation for numerical investigation.
• Systematically investigated optimal materials and structural parameters, including layer number and intermediate-layer material.
• Optimized a Pt/(0°, 138.5°, 27°) LGS/YX-LGS/SiC HAL structure.

Main Results:

• The proposed HAL structure demonstrated significant improvements in Q factor and FOM compared to conventional SAW structures.
• Achieved more than 5 times higher Q factor and 2.6 times higher FOM.
• The optimized structure shows promise for high-temperature SAW sensor development.

Conclusions:

• The developed HAL structure provides a viable method for enhancing the Q factor and FOM of LGS-based SAW devices.
• Offers valuable material and device structural design guidance for fabrication and high-temperature applications.
• The findings are critical for advancing high-temperature SAW sensor technology.