Diffusion coefficient of carbon in Fe-Ni alloy during synthesis of diamond under high temperature and high pressure

Synthetic diamond particles were prepared under high temperature and high pressure using arrayed seeds. A dense Fe-Ni alloy shell covered each diamond seed during synthesis; the growth of diamond particles was controlled by the diffusion of carbon through the metallic shell. The diffusion coefficient of carbon through Fe-Ni melt at 1600 K and 5.5 GPa is about 5×10−6 cm2/s, with an activation energy for diffusion of 336 kJ/mol.