Crystal structure of diamondlike carbon films prepared by ionized deposition from methane gas

Abstract
Diamondlike carbon films have been prepared by ionized deposition from methane gas. The film structures were examined by transmission electron microscopy, electron diffraction, and electron spectroscopy for chemical analysis techniques. It was found that the structure of the carbon films could be classified into three types: (i) amorphous, (ii) graphite, and (iii) cubic. These types depended mainly on the deposition conditions. Usually crystalline carbon films were diamond mixed with graphite showing an average grain size of several hundred angstroms. Very hard films were composed of diamond crystallites distributed in amorphous matrix.