X-ray absorption fine structure of diamond films grown by chemical vapor deposition

Abstract

We report the x-ray absorption spectra for two hard carbon films grown by filament-assisted chemical vapor deposition in gas mixtures of 1% and 0.18% methane in hydrogen. Although the Raman spectra of these two films suggest significant differences in structure, the x-ray absorption near-edge structure and extended x-ray absorption fine structure (EXAFS) are very similar. Analyzing the EXAFS from these films with a diamond crystal as a reference gives carboncarbon bond lengths of 1.53±0.03 Å. This result is consistent with diamond and incompatible with graphite. We conclude that the carbon films have the same local structure as diamond.

Underpotential Deposition of Cu on Boron-Doped Diamond Thin Films

“…The XANES spectra of the films (cleaned with the acidic procedure) are shown in Figure . The spectra of samples A and B, showing a modulated structure (with absorptions situated at 292.4, 298, and 305 eV) after the main absorption edge at 288.6 eV (sp 3 carbon hybridized), are very similar to the spectra of single-crystal diamond and to previously studied diamond thin films . Most importantly, the 1s π* transition (285.4 eV peak), which is associated with unsaturated carbon dangling bonds, is rather small in the two films.…”