Carbon 1s X-ray absorption spectra for reference materials

Carbon 1s or K-edge X-ray absorption spectra (XAS) were collected for reference materials using the 5.3.2.2 scanning transmission X-ray microscopy (STXM) instrument at the Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, United States. Spectra were collected using a photomultiplier (PMT) detector in transmission mode in the energy range of 280 to 320 eV. Monochromator calibration was accomplished using carbon dioxide gas with the characteristic Rydberg transitions set to 292.74 eV and 294.96 eV. A description of the instrument can be found in Kilcoyne et al. 2003: Kilcoyne, A.L.D., Tyliszczak, T., Steele, W.F., Fakra, S., Hitchcock, P., Franck, K., Anderson, E., Harteneck, B., Rightor, E.G., Mitchell, G.E. and Hitchcock, A.P., 2003. Interferometer-controlled scanning transmission X-ray microscopes at the Advanced Light Source. Journal of synchrotron radiation, 10(2), pp.125-136. The reference spectra were originally published in Toner et al. 2009. However, the spectra were not shared in digital form at that time: Toner, B.M., Fakra, S.C., Manganini, S.J., Santelli, C.M., Marcus, M.A., Moffett, J.W., Rouxel, O., German, C.R. and Edwards, K.J., 2009. Preservation of iron (II) by carbon-rich matrices in a hydrothermal plume. Nature Geoscience, 2(3), pp.197-201.