High resolution electron energy loss spectroscopy of hydrogenated polycrystalline diamond: Assignment of peaks through modifications induced by isotopic exchange

Preferential adsorption of thermally activated oxygen onto annealed polycrystalline diamond films studied by high resolution electron energy and X‐ray photoelectron spectroscopies

“…The vibrational mode at ∼155 meV is a superposition of a CC stretch and a CH bending vibration. The modes at ∼300 and 450 meV energy losses are pure CC vibrations; most likely the first and second overtones (or multiple losses) of the diamond optical phonon positioned at ∼150 meV 39. It was shown that diamond optical phonon overtones (or multiple losses) at 300, 450, and 600 meV appear solely on diamond surface with high purity and crystalline perfection 45.…”

“…Figure 2 shows HR‐EEL spectra of as‐deposited HF‐CVD diamond film and after annealing in vacuum at 1000 °C. The characteristic features of these spectra were extensively discussed in our previous works 39–41; herein these features are shortly described for convenience.…”

“…The HR‐EEL spectrum of the hydrogenated surface [Fig. 2(a)] is dominated by basic diamond loss features, which were extensively investigated by us and other groups previously 39, 40, 42–45. The vibrational mode at ∼155 meV is a superposition of a CC stretch and a CH bending vibration.…”

“…Following oxygen adsorption the 150 meV centered band significantly broadens [Fig. 6(a)] and now it may be decomposed into at least five different contributions: (i) 113 meV associated to carboxyl (CO) bending vibration 14; (ii) 125 meV associated to ether (COC) or peroxide (COOC) vibrations 21, 23; (iii) 137 meV associated to CH bending 48; (iv) 150 meV associated to diamond optical phonon 39; and (v) 180 meV mode associated to CH x bending modes 48. Peak fitting of CH stretching vibration [Fig.…”

Evidence for D2 dissociative chemisorption and electron affinity changes of bare and ion beam damaged polycrystalline diamond surfaces

“…HR-EELS measurements were carried out using a double monochromator and a single analyzer housed in a UHV system with a base pressure of 8×10 -10 Torr in a system previously described. [19] The HR-EELS spectra were recorded at RT up to loss energies of 500 meV. The primary electron energy was 5 eV and the spectra were recorded in the specular geometry at an incident angle of 55° from the surface normal.…”