Growth and characterization of nano diamond powder fabricated by microwave plasma torch

Abstract

A novel designed microwave plasma torch equipment has been setup for synthesizing the nano diamond powder (NDP). In this equipment microwave plasma can be maintained at rather high pressure with high flow rate of gas. The synthesis process has been performed using mixed gas of CH 4 and Ar or N 2 varied with gas flow rate and pressure. The size of synthesized NDP could be controlled from 20 to 50 nm and even bigger to micrometer. The structure and compositions of NDP have been analyzed by High Resolution Transmission Electron Microscopy (HRTEM) and Transmission ElectronEnergy Dispersion Spectroscopy (TED). The electron diffraction patterns yield good quality of crystalline for big NDP and amorphous structure for smaller NDP. Correlated X-Ray Diffraction (XRD) and Raman spectroscopy analysis revealed diamond property of NDP.