X-ray photoelectron spectroscopy research on superficial layer of cubic boron nitride crystals grown under HPHT
X. H. Fan, X. F. Guo, B. Xu, W. Zhang and L. C. Cai
Cubic boron nitride (cBN) crystals were synthesized with Li3N as catalyst under high pressure and high temperature (HPHT), the superficial layer of cBN crystal was investigated by X-ray photoelectron spectroscopy (XPS). It showed that the main elements existed in the layer were Li, B, N, O and C, and the B-N, B-C, B-O, C-O, C-C, Li-O-H and Li-C-O were the main bonding states. The further narrow-spectrum scanning results of B1s and N1s indicated that the main phases were hexagonal boron nitride (hBN) and cBN particles in the superficial layer. Moreover, the same results were achieved by X-ray diffraction (XRD). Therefore, it could be considered that the superficial layer played an important role in the cBN crystals growth under HPHT, and the existence of cBN particles would prompt the crystals growth by diffusion method.
Keywords: Cubic boron nitride; XPS; bonding state; superficial layer.