Electron energy-loss spectroscopy study of amorphization process of graphite bombarded with hydrogen ions and energetic electrons at low temperatures.

Structural change of graphite bombarded with hydrogen ions as well as energetic electrons is investigated mainly by the EELS (electron energy-loss spectroscopy) technique, with a focus on the formation of diamond-like amorphous (DLA) phase at low temperatures. The chemical effects of hydrogen ions on the amorphization process are examined by comparing the results obtained by hydrogen-ion bombardment with those obtained by electron bombardment. The critical temperatures for the formation of DLA phase during hydrogen-ion and electron bombardments are determined. Finally, a model of the amorphization process of graphite during ion-bombardment is presented.

High resolution shadowing for electron microscopy by sputter deposition.

The sputtering process by an ion beam well collimated and highly accelerated provides a valuable means of high resolution shadowing, replication of a fine object by a combination of pre-shadowing and deposition as well as a preparation of supporting films. High resolution shadowing and films with grains smaller than 1 nm can be obtained by argon ion-sputtering targets of tungsten and tungsten/tantalum alloy. The resolution of carbon replicas pre-shadowed with tungsten/tantalum is determined from the radius of curvature of replicated magnesium oxide crystal corners.