Study of oxygen-C 60 compound formation by NEXAFS and RIXS

Abstract

The interaction of oxygen with C60 molecules was studied on a C60 film which had been exposed simultaneously to oxygen and UV-light for 190 hours, producing an approximately C60O1 stoichiometry in the bulk of the sample. C K-edge and O K-edge NEXAFS (using total fluorescence yield detection) and resonant X-ray inelastic scattering (RIXS) spectra from the sample film were measured and the C K-edge data were compared to the spectra from pristine C60 as reference. The C K-edge absorption and emission spectral profiles of the oxygen-doped sample are similar to those of the C60 reference, suggesting that cage breaking of C60 under these conditions, if any, is negligible. However, the redistribution of intensities in the spectra indicates changes in the occupancies of different molecular orbitals, possibly due to changes in electron density upon reaction. Similarities of the O K-edge soft X-ray emission (SXES) spectra to several small oxygen-containing molecules is being discussed in terms of bonding models.PACS. 73.61.Wp Fullerenes and related materials -33.50.Dq Fluorescence and phosphorescence spectra -33.20.Rm X-ray spectra

Density functional theory calculations of the non-resonant and resonant X-ray emission spectroscopy of carbon fullerenes and nanotubes

“…The computed spectrum is closest to the spectrum at an excitation energy of 283.9 eV which corresponds to the rising edge of the intense core! ⇡ ⇤ band [39]. We note that the simulation of the RIXS spectrum may be improved through the use of the Kramers-Heisenberg approach [48,49], however, such an approach is currently beyond our current capabilities for a system the size of C 60 .…”

“…For both of these molecules, the distinct bands present in the X-ray emission spectrum of C 60 are not evident and only a broad peak is observed. RIXS spectra have been reported for C 60 and C 70 [38,39]. For C 60 there is a significant variation between the spectra excited at di↵erent photon energies.…”

X-ray Fluorescence Spectroscopy of Novel Materials

“…In particular, a large body of experimental data on the electronic structure of strongly correlated compounds of d and f metals [110][111][112][113][114][115][116][117][118][119], fullerenes [6,[120][121][122][123], molecular magnets [124][125][126][127], and new layered MgB 2 -type superconductors [31,[128][129][130][131][132] is left beyond the scope of this review, as is the influence of polarization effects on RIXS spectra [133−138]. The method in question is expected to progress along several lines.…”

Core-Hole Excitation Spectra of the Oxides and Hydrates of Fullerene C60 and Azafullerene C59N

“…The NEXAFS and XES spectra of carbon K-edges of the selected molecules, including the open [5,6] and closed [6,6] For the C59N molecule, the contributions from β-spin electrons were marked as negative numbers. Experimental NEXAFS spectra of C60, [6,6]C60O [51] and (C59N)2 molecules [52] have been shifted −0.5 eV (shown as dashed lines). (b) Simulated XES spectra at the carbon K-edge of the fullerene C60, aza [60]fullerene C59N, their oxides and hydrates and (C59N)2.…”