ESR and X-ray diffraction studies of the CVD diamond films

Thin polycrystalline diamond films were prepared by thermal decomposition of hydrocarbon and hydrogen in the presence of a hot tungsten filament (HF CVD technique). Electron Spin Resonance (ESR) spectroscopy investigations were carried out and correlated to diamond microcrystal size estimated on the basis of X-ray diffraction (XRD) measurements. It was shown that both ESR signal and average crystal size of the thin CVD diamond films depend strongly on the ratio of hydrocarbon/hydrogen concentrations in the CVD reactor. XRD spectra indicate the presence of fullerene and graphitic polytypes in most studied samples, independent of growth conditions. Observed reciprocal proportionality of the ESR signal intensity versus diamond grain size suggests that the above mentioned carbon phases are mainly dispersed al the grain boundaries.