The stress state in bismuth to 298 GPa and its use as a pressure transmitting medium and pressure marker at multi-megabar pressures

We have conducted diffraction studies of bismuth (Bi) to 298 GPa using both conventional and toroidal diamond anvil cells (DACs) to investigate its suitability as a pressure-transmitting medium (PTM) to such pressures. Using microfocused x-ray beams, we have determined the pressure dependence of the uniaxial stress component (t) in cubic Bi-V from 7 to 298 GPa and find that at 298 GPa, t, 0:5 GPa. Bi-V, therefore, cannot support significant shear stresses, making it an excellent PTM. We have also measured the compressibility of Bi-V against that of copper (Cu) and gold (Au), allowing it to be used as a pressure marker as well as a PTM. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

We conducted diffraction studies on bismuth (Bi) up to 298 GPa using conventional and toroidal diamond anvil cells (DACs) to investigate its suitability as a pressure-transmitting medium (PTM). By utilizing microfocused x-ray beams, we determined the pressure dependence of the uniaxial stress component (t) in cubic Bi-V and found that at 298 GPa, t was 0.5 GPa. This indicates that Bi-V cannot support significant shear stresses, making it an excellent PTM. Additionally, we measured the compressibility of Bi-V compared to copper (Cu) and gold (Au), enabling its use as both a pressure marker and PTM.