Diamond synthesis by shock compression from a thin graphite plate with suppressed regraphitization Original Research Article

Shock synthesis of diamond was carried out at pressures of 26, 55, and 83 GPa by applying a quenching technique; a thin graphite plate was sandwiched by the copper heatsink disks. Successful suppressing of reverse transition to graphite (regraphitization) was achieved in the present technique. Thin sections were prepared from the recovered samples to observe distribution of the products between the heatsinks by TEM in detail, and a numerical analysis of histories of pressure and temperature distributions in the sample was performed. Combining the observed results with the numerical analyses, a relationship between regraphitization and cooling rates estimated at different distances from the heatsink was examined, and effects of pressure, temperature, and microtexture of the starting material on the transition ratio of graphite to diamond were also discussed.