Iron etching of diamond in hydrogen-free atmosphere

Diamond surface was etched by iron powder in hydrogen-free atmosphere. Scanning electron microscopy (SEM), laser probe analyzer (LPA) and X-ray Diffractometer (XRD) were used to characterize the surface morphology, pit depth, structure and composition of the etched diamond. The etching behavior of diamond was also analyzed.The results show that iron powder can etch diamond crystals through its catalysis in hydrogen-free atmosphere. The etching is mainly carried out on {111} and {100} surfaces of diamond, and the etching rate of {100} surfaces is higher than that of {111} surfaces. The etching mechanism is realized by the formation of Fe-C phase between iron and diamond. The etching is influenced by the content of iron phase and the structure of diamond remains unchanged after etching.