Deposition of polycrystalline diamond films with a controlled grain size by periodic secondary nucleation

This paper presents a new method for the synthesis of polycrystalline diamond films with a controlled grain size, based on the principle of creating a multilayer coating structure by periodic bias-induced secondary nucleation. By this technique, we synthesized diamond films with a thickness of up to 120 mu m and a grain size of up to 1 mu m. The diamond multilayer films obtained were characterized by scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD). The effect of different deposition parameters on nucleation density was also discussed. This method shows considerable promise for the synthesis of thick diamond coatings with low roughness and internal stress. (C) 2016 The Authors. Published by Elsevier Ltd.