Characterization of carbon films on the Japanese smoked roof tile "Ibushi-Kawara" by high-resolution soft X-ray spectroscopy

Muramatsu, Yasuji; Motoyama, Muneyuki*; Denlinger, J. D.*; Gullikson, E. M.*; Perera, R. C. C.*

Carbon films on Japanese smoked roof tile "Ibushi-Kawara" were characterized by high-resolution soft X-ray spectroscopy using synchrotron radiation. By comparing the soft X-ray emission and absorption spectra of Kawara with the reference carbon compounds, it was determined that the carbon films on Kawara consist of mostly carbon-black-like sp2 carbon atoms and that the surface also contains polyethylene-like sp3 carbon atoms. The take-off/incident-angle dependence on the X-ray emission/absorption spectra of Kawara implies that the carbon-black-like sp2 carbon atoms partially form a layer structure parallel to the basal clay plane. From the take-off-angle dependence of the p/s-peak intensity ratio in the X-ray emission spectra, the layer ordering of the carbon films is estimated to be 50% of highly oriented pyrolytic graphite (HOPG). Therefore, the metallic oxidized color and durability are due to the layer structure and the random structure that connects the layer-structured clusters, respectively.