CONTROL OF DISTRIBUTIONS AND SIZES OF NANOCOMPOSITE CARBON PARTICLES

Microscale to nanoscale carbon and carbon nitride particles and films were synthesized by using plasma discharge sputtering deposition techniques. Experimental results indicated that sizes and distributions of the particles were directly determined by both discharge voltage and bias voltage. Sputtering deposition at high discharge voltages yielded large sizes (micrometer order) of particles with a high disorder of distribution. Whereas sputtering deposition at low discharge voltages yielded nanoscale of particles that uniformly distributed on the surface of the substrate. Ar laser beam in combination with an optical microscope has been used, enabling one to remove these particles and to achieve preferred distributions of the particles. Low growth rate of the films was found at the low voltage discharge sputtering deposition. Bias voltage was employed during the experiments in order to speed up the growth rate and increase nitrogen content inside the carbon nitride film. With an increase of the bias voltage up to 5 kV, nanoparticles appeared in two-dimensional, sunflower type of cluster distributions. Typical G, D, and C=N bands in the Raman spectra of the samples were identified.