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

Abstract

A new double neptunium zirconium phosphate of the type MZr(PO) (M = Np), crystallizing in the structure type NaZr(PO) (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 P3[combining macron]c, the same as that for the lanthanide analogues LnZr(PO). 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.

Unveiling the Synergistic Effect of Magnetite and ZrPO4 for Highly Selective Removal of Anionic Azo Dyes via an Ion-Exchange Process

“…The bands appearing at 967 and 1063 cm –1 correspond to symmetric and asymmetric stretching of the P–O bond (Figure S3b). Both characteristic bands of ZrPO 4 NPs and Fe 3 O 4 NPs can be found in Figure S3c, which strongly supports the formation of nanocomposite FZ.…”

Phase‐Bridged Hierarchical Catalysts for Efficient and Stable Water Electrolysis

“…These results indicate that the phosphorus incorporated into NiCu−LDH strongly interacts with the constituent metal and oxygen to form phosphides, while retaining the LDH structure. [40,41] Subsequently, the Tauc plot slope constructed using data recorded by UV-vis-NIR spectroscopy (Figure S5c,d, Supporting Information) was analyzed to elucidate the structural and electronic properties of the samples. The calculated band gap of P−NiCuFe 0.06 −LDH (1.95 eV), originating from charge redistribution on the surface of the activated P−NiCuFe 0.06 −LDH, was considerably lower than that of NiCu−LDH.…”

Periodic trends in trivalent actinide halides, phosphates, and arsenates

“…61,82–85 1 : 1 trivalent neptunium phosphate has not been observed according to the literature, however, a double salt of Np( iii ) and zirconium with phosphate ion was reported. 86 Tetravalent neptunium phosphates have been reported in the past. 44,45,87 Plutonium reacts with fluorine, chlorine, bromine, and iodine to give the respective trihalides.…”