Synthesis and investigation of neptunium zirconium phosphate, a member of the NZP family: crystal structure, thermal behaviour and Mössbauer spectroscopy studies

Journal article (2017)

Authors

D. Bykov RST/Reactor Physics and Nuclear Materials - AS
R.J.M. Konings European Commission Joint Research Centre, Institute for Transuranium Elements Karlsruhe
C. Apostolidis European Commission Joint Research Centre, Institute for Transuranium Elements Karlsruhe
A. Hen European Commission Joint Research Centre, Institute for Transuranium Elements Karlsruhe
E Colineau European Commission Joint Research Centre, Institute for Transuranium Elements Karlsruhe
T Wiss European Commission Joint Research Centre, Institute for Transuranium Elements Karlsruhe
P. Raison European Commission Joint Research Centre, Institute for Transuranium Elements Karlsruhe
Research Group
RST/Reactor Physics and Nuclear Materials (AS) (TU Delft)
Copyright: © 2017 D. Bykov, R.J.M. Konings, C. Apostolidis, A. Hen, E Colineau, T Wiss, P. Raison
DOI
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https://doi.org/10.1039/C7DT02110K
More Info
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Published Date

23-08-2017

Language

English

Faculty

Applied Sciences

Department

RST/Radiation, Science and Technology

Research Group

RST/Reactor Physics and Nuclear Materials

Abstract

A new double neptunium zirconium phosphate of the type MxZr2(PO4)3 (M = Np), crystallizing in the structure type NaZr2(PO4)3 (NZP, NASICON), was synthesized by solid state reactions at high temperatures and characterized by X-ray diffraction, infrared spectroscopy and Mössbauer spectroscopy. The Rietveld refinement of the XRD pattern together with the analysis of the IR spectra of the sample confirmed the space group P[3 with combining macron]c, the same as that for the lanthanide analogues Ln0.33Zr2(PO4)3. However, Mössbauer studies revealed the presence of neptunium in the two oxidation states +3 and +4, indicating a two-phase NZP system with different crystallographic environments of the neptunium atoms. The thermal behaviour of the sample was followed up to 1400 °C by thermogravimetric analysis.