The growth mechanism of B/N co-doped diamonds under high pressure and high temperature

The B/N co-doped diamonds have been successfully fabricated in the graphitic mixtures of C and BN system with Fe-Ni alloy as catalyst under high pressure and high temperature conditions. Morphology and structural properties of the synthesized samples are characterized by optical microscope, scanning electron microscopy and X-ray diffraction. Raman spectrum and X-ray photoelectron spectroscopy are used to confirm their chemical composition and atomic-level hybrid qualities. Our results indicate that B, C and N combined with each other and formed stable chemical bonds in B/N co-doped diamonds, and the h-BN additive played an important role in determining the morphology of diamond crystal. The B/N co-doped diamond shows strip shape elongated along the {111} direction. According to our results, the possible growth mechanism is discussed.