HPHT synthesis of diamond in the system of (FeMn)_xAl_(1-x) and carbon

In this work,the diamond crystals were synthesized in a(FeMn)_xAl_((1-x))-C system at 5.6~5.8 GPa and 1400 ~ 1600 ℃.The color,morphology,nitrogen content and inclusions of synthetic diamond crystals were characterized by optics microscope(OM),scanning electronic microscope(SEM),micro infra-red spectra,Mssbauer spectra respectively.The results have shown that the additive Al has a significant influence on the color of crystals,growth rate,and inclusions etc.The color of diamond crystals synthesized without additive Al is yellow,while that with additive Al becomes light and nearly disappears.The growth rate of synthetic diamond crystals without additive Al is rapider than that with additive Al.The nitrogen content of diamond crystals without additive Al is higher than that with additive Al.The inclusions in diamond crystals synthesized without additive Al is mainly Fe and Fe_3C,while that with additive Al is FeAl alloy.