Characterization of diamonds synthesized with h-BN doped under high pressure and high temperature

Abstract

There is a strong interaction between nitrogen and boron in diamonds. In this paper, boron-nitrogen co-doped diamonds were successfully synthesized at 5.6 GPa and 1300–1350 ℃ with Ni-Mn-Co alloy as a catalyst. The effect of nitrogen on boron-doped diamond (BDD) was further investigated by adding the nitrogen getter to the system. The measurement results of the two groups of crystals showed that nitrogen greatly influenced the growth behavior of BDD. A small nitrogen amount in BDDs could accelerate the growth rate and improve the quality of crystals. In contrast, a high nitrogen concentration decreased the growth rate and created macroscopic defects. The Fourier transform infrared spectroscopy (FTIR) results demonstrated the presence of N+ centers in boron-nitrogen co-doped diamonds. X-ray photoelectron spectroscopy (XPS) characterization of boron-nitrogen co-doped diamond confirmed that boron atoms entered the diamond lattice and combined with nitrogen atoms to form B-N bonds. This work reveals the effect of nitrogen on the properties of BDDs and provides insight into the interaction between boron and nitrogen in diamonds.