Abstract
Two transitions in the bonding are found in tetrahedral amorphous carbon (ta-C) films as a function of deposition temperature. The total sp3 fraction shows a sharp decrease at a transition temperature of order 250°C. In contrast, visible Raman finds that the sp2 sites show a gradual ordering into the graphitic clusters through the sharp bonding transition. The optical gap and resistivity show a similar, gradual transition. This indicates that the sp2 cluster size determines the optical gap, even when the sp2 content does not change. The Raman I(D)/I(G) peak ratio is found to vary inversely with the square of the gap.
Original language | English |
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Pages (from-to) | 1419-1421 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 76 |
Issue number | 11 |
DOIs | |
Publication status | Published - Mar 13 2000 |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)