Ultrahigh pressure cell for materials synthesis

We describe here an apparatus for generating ultrahigh pressures and temperatures for materials synthesis. The system uses a spherically shaped explosive charge to radially compress various materials contained within the sample cavity. The results show the system is completely reproducible and, because of the geometry of the loading system, the workpiece that holds the precursor material is in excellent postshock condition. Samples are subjected to a pressure pulse of approximately 230 GPa for a period of 4 μs. Using this system, C 60 has been compressed using a variety of quenching materials to attempt to generate diamond. Two organic precursors have also been tested to determine if the high stress conditions are suitable to synthesize β-carbon nitride. In this article, the design of the system, the numerical modeling using Dyna East Finite Element Lagrangian and CTH hydrocodes, and the results of the synthesis experiments will be presented.