High-pressure generation above 45 GPa over a 10 mm3 volume with a multi-anvil press

Area of Science:

• High-pressure physics and materials science.
• Geophysics and planetary science.

Background:

• Multi-anvil presses are crucial for high-pressure research.
• Current limitations restrict pressures below ~25 GPa for millimeter-scale samples.

Purpose of the Study:

• To extend the pressure range achievable in multi-anvil presses for large sample volumes.
• To optimize the Kawai-cell assembly for enhanced pressure generation.

Main Methods:

• Systematic optimization of the Kawai-cell assembly using tungsten carbide anvils (3 mm TEL).
• Investigated the effect of anvil tapering and gasket volume on pressure generation.
• Utilized ultrahard tungsten carbide anvils (TJS01, Fujilloy) with a 1° taper.

Main Results:

• Anvil tapering alone had a negligible effect on pressure for large sample volumes.
• Reducing gasket volume significantly improved press-load transmission, increasing pressure by ~33%.
• Achieved pressures up to 45.8 GPa with a sample volume >10 mm³ and anvil gap >0.3 mm.

Conclusions:

• Optimized gasket design is key to achieving ultra-high pressures (>45 GPa) in large-volume multi-anvil presses.
• This breakthrough facilitates the synthesis of novel materials and advanced physical property measurements.
• Enables precise measurements (ultrasonic interferometry, electrical impedance, thermal conductivity) at unprecedented pressures.