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

高分解能軟X線分光法を用いたいぶし瓦表面炭素膜のキャラクタリゼーション

村松 康司; 元山 宗之*; Denlinger, J. D.*; Gullikson, E. M.*; Perera, R. C. C.*

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

軟X線発光・吸収分光法により、いぶし瓦表面炭素膜の化学状態を分析した。その結果、この炭素膜は基本的にカーボンブラックと同様なsp2炭素からなるものの、その半分は粘土基板にほぼ平行な層構造をもち、残り半分の炭素は非晶質構造をもつことがわかった。いぶし瓦の光沢色はこの層構造成分に起因し、耐久性は非晶質構造に起因することが示唆された。

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.