NEXAFS analysis and electronic state of cesium in clay minerals

Suzuki, Chikashi ; Yoshida, Hiroyuki  ; Shuk, D. K.*; Suzuki, Shinichi; Yaita, Tsuyoshi

We evaluated Cs M near edge X-ray absorption fine structure (NEXAFS) of Cs halides and clay minerals containing Cs using DFT calculation with the NEXAFS of the clay minerals measured. The evaluation of Cs halides indicated that the core-hole strength (CHS) in the NEXAFS measurement was reduced to 0.6, taking into account the strength interaction of the core-hole with the valence-band electrons. On the basis of this result, Cs M NEXAFS of the clay mineral was well reproduced including the dominant peak and tail structures using DFT calculation. Moreover the calculation showed that the NEXAFS clearly changed with the displacement of Si atoms to Al in the six-membered ring of clay minerals and little did with the coexist of K atoms with Cs between layers of the clay mineral. In addition, we examined the electronic state of CsCl and the clay mineral containing Cs.