Synthesis and characterization of uranium(IV)-bearing members of the [NZP] structural family

Journal Article · Fri Oct 01 04:00:00 EDT 1999 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm990209f· OSTI ID:20001159

Hawkins, H T; Spearing, D R; Veirs, D K; Danis, J A; Smith, D M; Tait, C D; Runde, W H; Spilde, M N; Scheetz, B E

The sodium dizirconium tris(phosphate) structural family ([NZP]) includes compounds that may be represented by the general formula M{prime}M{double{underscore}prime}{sup 1--3}A{sub 2}(PO{sub 4}){sub 3}. The ability of KXr{sub 2}(PO{sub 4}){sub 3}, a member of the [NZP] structural family, to accommodate U(IV) on the octahedrally coordinated A site has been demonstrated for compounds in the series KZr{sub 2{minus}x}U{sub x}(PO{sub 4}){sub 3} (0 {le} x {le} 0.20)(KZ series). KU{sub 2}(PO{sub 4}){sub 3}, the end member of the series, was found to adopt a monoclinic structure with 9-fold coordination of U(IV) that does not belong to the [NZP] family. The compounds were prepared from sol-gel derived precursors in an argon environment. X-ray microanalyses indicated that the precursor powders had reacted fully to produce compounds of the expected stoichiometries. Rietveld refined X-ray powder diffraction data of the KZ series confirmed a rhombohedral (R) structure and suggested random occupation of the A site by U/Zr. The presence of U(IV) was established by comparison of the UV/vis spectra of the KZ series with those of other U(IV) phosphates. The Rietveld refined data show an increase in the volume of the R cell with increasing values of x. The structure of KU{sub 2}(PO{sub 4}){sub 3}, determine from Rietveld refinement of powder X-ray diffraction data, is monoclinic.

• Research Organization: Los Alamos National Lab., New Mexico (US)
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 20001159
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 10 Vol. 11; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
MONOCLINIC LATTICES
SODIUM PHOSPHATES
SOLID SOLUTIONS
URANIUM PHOSPHATES
ZIRCONIUM PHOSPHATES