TEM and DSC studies on the synthetic diamond grown from Fe-Ni-C-B system under HPHT

摘要

Transmission Electron Microscope (TEM) and Different scanning calorimetry (DSC) methods were used to investigate the diamonds grown with different boron content alloy catalysts under high-pressure high-temperature (HPHT). Experimental results demonstrated the microstructure and composition of boride compounds in synthetic diamond, such as (FeNi)_(23)(CB)_6, (Fe, Ni)_3(C,B), (Fe,Ni)B and B_4C, whose formation process was analyzed. The thermal stability of diamond depends on boron concentration in catalyst according to DSC studies. We analyzed the reason of diamond oxidation. The work offers valuable information for improving the thermal stability of synthetic diamond crystals by adjusting boron content in the Fe-Ni based catalyst.