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Diffuse reflectance spectroscopy of neptunium ions in polycrystalline ceramics designed for immobilization of HLW

Journal Article


Abstract


  • Diffuse reflectance spectra at room temperature have been collected on polycrystalline perovskite (CaTiO3), zirconolite (CaZrTi2O7) and thorutite (ThTi2O6) samples doped with Np. The Np species give rise to a number of broad, unresolved intraconfigurational f-f electronic transition bands in the near-infrared and visible spectral regions. Both Np3+ and Np4+ can substitute in the Ca site of perovskite by the appropriate choice of charge compensation and sintering atmosphere. No detectable spectral differences were observed when Np4+ was targeted towards either the Ca or Zr sites in zirconolite. Np4+ but not Np5+ can be incorporated in the Th site of thorutite by sintering in air. Even in the most dilute [≤ 0.03 formula units (f.u.)] Np4+ samples of the different titanates studied, there was only very approximate agreement with the Kubelka-Munk law. Crown Copyright © 2007.

Publication Date


  • 2007

Citation


  • Zhang, Y., Vance, E. R., Begg, B. D., & Li, H. (2007). Diffuse reflectance spectroscopy of neptunium ions in polycrystalline ceramics designed for immobilization of HLW. Journal of Alloys and Compounds, 444-445(SPEC. ISS.), 598-602. doi:10.1016/j.jallcom.2007.01.055

Scopus Eid


  • 2-s2.0-34548126551

Web Of Science Accession Number


Start Page


  • 598

End Page


  • 602

Volume


  • 444-445

Issue


  • SPEC. ISS.

Abstract


  • Diffuse reflectance spectra at room temperature have been collected on polycrystalline perovskite (CaTiO3), zirconolite (CaZrTi2O7) and thorutite (ThTi2O6) samples doped with Np. The Np species give rise to a number of broad, unresolved intraconfigurational f-f electronic transition bands in the near-infrared and visible spectral regions. Both Np3+ and Np4+ can substitute in the Ca site of perovskite by the appropriate choice of charge compensation and sintering atmosphere. No detectable spectral differences were observed when Np4+ was targeted towards either the Ca or Zr sites in zirconolite. Np4+ but not Np5+ can be incorporated in the Th site of thorutite by sintering in air. Even in the most dilute [≤ 0.03 formula units (f.u.)] Np4+ samples of the different titanates studied, there was only very approximate agreement with the Kubelka-Munk law. Crown Copyright © 2007.

Publication Date


  • 2007

Citation


  • Zhang, Y., Vance, E. R., Begg, B. D., & Li, H. (2007). Diffuse reflectance spectroscopy of neptunium ions in polycrystalline ceramics designed for immobilization of HLW. Journal of Alloys and Compounds, 444-445(SPEC. ISS.), 598-602. doi:10.1016/j.jallcom.2007.01.055

Scopus Eid


  • 2-s2.0-34548126551

Web Of Science Accession Number


Start Page


  • 598

End Page


  • 602

Volume


  • 444-445

Issue


  • SPEC. ISS.