High-pressure generation using high-purity synthetic type IIa diamond anvils

Abstract

High-pressure generation tests were conducted using synthetic type IIa diamond anvils with various shapes and orientations, and their deformation and fracture were investigated under high pressure. The synthetic diamond anvils with bevelled culet of less than 50 μm in diameter can generate pressures of up to 200 GPa with good reproducibility and without emitting any luminescence. The pressure generating efficiency of the (111) diamond anvil is slightly higher than that of the (100) diamond anvil. At pressures higher than 200 GPa, however, both of the (100) and (111) synthetic diamond anvils emit strong luminescence due to plastic deformation. The plastic deformation seems to be caused by the steep cupping deformation in the culet, leading to fracture of the anvil.

Keywords:

• synthetic diamond
• diamond anvil
• high pressure
• plastic deformation

Acknowledgements

The authors thank K. Takemura and S. Nakano for their help with some experiments in this study.