Nature of Carbon-Carbon Bonding in Evaporated and Ion-Sputtered (Diamondlike) Amorphous Carbon from (e, 2e) Spectroscopy

The local carbon-carbon bonding in evaporated ($e$-C) and ion-sputtered ($i$-C) amorphous carbon has been investigated by transmission electron-energy-loss spectroscopy (EELS) and by ($e, 2e$) spectroscopy. The EELS data indicate that the $e$-C is graphiclike and the $i$-C is diamondlike. The ($e, 2e$) data demonstrate that the concentration of $s{p}^2$ bonding is ∼100% in both materials ($0.85\le c_{s{p}^2}\le 1.0$) for $e$-C and $0.75\le c_{s{p}^2}\le 1.0$ for $i$-C). There is significant rehybridization of the $\pi$ orbital in $i$-C.