Synthesis and Characterization of New BCN Diamond under High Pressure and High Temperature Conditions

In this paper, the graphitic mixtures of C and BN have been subjected to high pressure and high temperature (HPHT) conditions to study the crystallization of the cubic phase, and new diamond crystals doped with B and N atoms (BCxN) were successfully synthesized with iron and nickel as catalysts. The morphology and characterization of our obtained diamond changed significantly, which was attributed to the incorporation of the B and N atoms into the crystal structure. In addition, we detected that the cubic phases obtained in the C-0.9(BN)(0.1) system were separated because of the different B/N ratio, while in the C-0.5(BN)(0.5) system no phase separation was found and the obtained BCN diamond exhibited cuboctahedral shape, light yellow in color, and nearly transparent. According to our results, two possible reaction routes were introduced for the crystallization of diamond in the graphitic mixtures of C and BN. Moreover, X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy were used to confirm their chemical composition and atomic-level hybrid qualities. Our results show that new B-C-N compounds can be synthesized by doping B and N atoms in diamond crystals under HPHT conditions, and it may become a new effective method in the future study of the preparation of cubic B-C-N alloys.