Diamond-based HBAR as a high-pressure sensor

Area of Science:

• Materials Science
• Condensed Matter Physics
• Acoustics

Background:

• High-pressure research requires accurate and sensitive measurement tools.
• Existing pressure sensors have limitations in performance and sensitivity.
• High-overtone Bulk Acoustic Resonators (HBARs) offer potential for novel sensing applications.

Purpose of the Study:

• To develop and evaluate an integrated measurement system using an HBAR as a high-pressure sensor.
• To investigate the feasibility of using a specific HBAR configuration within a Diamond Anvil Cell (DAC).
• To calibrate the HBAR sensor using established high-pressure calibration methods.

Main Methods:

• Development of an integrated system combining a DAC and an HBAR operating in the microwave frequency band (1.3–3.7 GHz).
• Fabrication of a specific HBAR configuration: "Al/ASN/Mo/(100) diamond".
• Calibration of the HBAR sensor using two independent methods: diamond Raman line shift and ruby R1 luminescence line shift.

Main Results:

• A stable correlation was established between HBAR frequency shifts and applied pressure (0–30 GPa).
• The sensitivity of the HBAR sensor was determined to be 4.8 × 10^-4 GPa^-1.
• The developed sensor demonstrated superior performance and sensitivity compared to existing methods in the 0–5 GPa range.

Conclusions:

• The integrated HBAR-DAC system is a viable and effective high-pressure sensor.
• The proposed HBAR configuration exhibits high sensitivity and stable performance.
• This acoustoelectronic sensor offers significant advantages for high-pressure measurements, particularly in the lower GPa range.