Measurement of Pressure Distribution in Pressure Media under Very High Pressure in a Diamond Anvil Cell and Estimation of Their Friction Factor

Abstract

Pressure distribution under high pressure around 5GPa were measured in a diamond anvil cell for four kinds of pressure media, such as pyrophyllite etc. Lorentzian-like pressure profiles with different line width (FWHM) in each pressure medium were observed. The order of line width value was α-Fe₂O₃<pyrophyllite<NaCl<Cu. Pressure distributions obtained experimentally were simulated using rigid plastic FEM. Steep pressure distributions in pyrophyllite and α-Fe₂O₃ were well fitted on the assumption that friction factor m was proportional to the power of pressure until m=1. These results are expected to contribute to an efficient design of a high pressure apparatus.