Interaction between Ultra-Trace Amount of Cesium and Oxides Studied by Total-Reflection X-Ray Photoelectron Spectroscopy

• Baba Yuji

  Sector of Fukushima Research and Development, Japan Atomic Energy Agency

• Shimoyama Iwao

  Quantum Beam Science Center, Japan Atomic Energy Agency

• Hirao Norie

  Quantum Beam Science Center, Japan Atomic Energy Agency

• Izumi Toshinori

  Quantum Beam Science Center, Japan Atomic Energy Agency

Bibliographic Information

Other Title

• Interaction between ultra-trace amount of cesium and oxides studied by total-reflection X-ray photoelectron spectroscopy e-J

Abstract

In order to clarify the chemical states of radioactive cesium sorbed in minerals such as clay, soil, sand and rock, X-ray photoelectron spectra (XPS) have been measured for cesium adsorbed on SiO₂ and Al₂O₃ (sapphire), which are major components of these minerals. Since the number of atoms in radioactive cesium (¹³⁴Cs or ¹³⁷Cs) is extremely small, total reflection XPS (TR-XPS) using synchrotron radiation was applied in order to measure trace amount of cesium. For SiO₂ surface, it was shown that ultra-trace amount of cesium down to 205 pg·cm⁻² can be detected by TR-XPS. This amount corresponds to about 400 Bq of ¹³⁷Cs (t_1/2=30.2 y). Thus it was demonstrated that the ultra-trace amount of cesium corresponding to the radioactive cesium level can be measured by TR-XPS. As to the chemical states of cesium, the binding energy of the Cs 3d_5/2 line for cesium adsorbed on SiO₂ and Al₂O₃ ranges from 725.2 eV to 725.5 eV irrespective of the adsorption conditions, suggesting that the cesium is adsorbed through weak Van-der-Waals force. While after rinsing the cesium-adsorbed SiO₂ in water, the binding energy of the Cs 3d_5/2 line shifted by 0.8 eV to higher energy side. The result indicates that the ultra-trace amount cesium remaining after rinsing is covalently bonded with the SiO₂ surface rather than ionically bonded. [DOI: 10.1380/ejssnt.2015.417]

Journal

• e-Journal of Surface Science and Nanotechnology

  e-Journal of Surface Science and Nanotechnology 13 (0), 417-421, 2015

  The Japan Society of Vacuum and Surface Science

Keywords

• X-ray photoelectron spectroscopy
• Synchrotron radiation photoelectron spectroscopy
• Silicon oxides
• Aluminum oxide
• Physical adsorption
• Alkali metals

Details

• CRID: 1390282680163948160
• NII Article ID: 130005096314
• DOI: 10.1380/ejssnt.2015.417
• ISSN: 13480391
• Web Site: https://www.jstage.jst.go.jp/article/ejssnt/13/0/13_417/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed