Sub-nanoscale polishing of single crystal diamond(100) and the chemical behavior of nanoparticles during the polishing process

Abstract

Single crystal diamond is widely utilized in various high-tech fields due to its many excellent properties, but poor surface quality will affect its applications. Therefore, increased ability to process high-quality diamond will dramatically expand its applications in high-tech fields. A combination of mechanical grinding and chemical mechanical polishing was utilized to propose a new room-temperature polishing method, by means of abrasive particles and transition metal ions. This process activated the diamond surface and resulted in an ultra-smooth surface of Ra 0.452 nm and rms 0.572 nm (measurement area: 283 μm × 212 μm), as well as a monoatomic surface layer of Ra 0.115 nm and rms 0.145 nm in a local region (measurement area: 500 nm × 500 nm). The chemical behavior of nanoparticles during the polishing process was studies via reactive force field molecular dynamics simulation. The surface chemical behaviors of both abrasive particles and diamond substrate during the polishing process were elucidated by combining experiments with simulations and the diamond removal mechanism and activated mechanism of Fe2+ were explored. This work provides a theoretical basis and technical support for the ultra-precision machining of single crystal diamond.