Synthesis, characterization and structural refinement of polycrystalline uranium substituted zirconolite CaZr0.9U0.1Ti2O7
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Omprakash Shrivastava
Summary
Ceramic precursors of Zirconolite (CaZrTi2O7) family have a remarkable property of substitution on Zr4+ cationic sites. This makes them a potential material for nuclear waste management in ‘synroc’ technology. In order to simulate the mechanism of partial substitution of zirconium by tetravalent actinides, a solid phase of composition CaZr0.9U0.1Ti2O7 was synthesized through ceramic route by taking calculated quantities of oxides of Ca, Ti and nitrates of uranium and zirconium, respectively. Solid-state synthesis was carried out by repeated pelletizing and sintering the finely powdered oxide mixture in a muffle furnace at 1050 °C. The polycrystalline solid phase was characterized by its typical powder diffraction pattern. Step analysis data were used for ab initio calculation of structural parameters. The SEM and EDAX analysis also confirm that the zirconolite acts as a host material for uranium. The powder diffraction data of 3500 points for 2θ=10°-80° has been analysed by GSAS (general structure analysis system) software to obtain the best fit of the observed data points. The uranium substituted zirconolite crystallizes in monoclinic symmetry with space group C2/c (#15). The following unit cell parameters have been calculated: a=12.5615(13), b=7.2743(8), c=11.5103(33) and β=101.086(14). The calculated and observed values of the intensities, lattice parameters and density measurement show good agreement. The Rietveld analysis and GSAS based calculations for bond distance Ti-O, Ca-O, Zr-O, and O-M-O bond angles were made. The structure was refined to satisfactory completion. The Rp and Rwp were found to be 0.1583 and 0.2097 respectively. The crystal data of the title compound show that increase in U content results in expansion of the zirconolite unit cell.
© by Oldenbourg Wissenschaftsverlag, München
Artikel in diesem Heft
- Preface - Special Issue: NUCAR 2005
- Incomplete fusion mechanism in 16O + 93Nb reaction at 6 MeV/nucleon: Recoil range measurements
- Extraction of actinides using N, N, N′, N′-tetraoctyl diglycolamide (TODGA): a thermodynamic study
- Extraction of neptunium(IV) by a mixture of 3-phenyl-4-acetyl-5-isoxazolone and tri-n-octyl phosphine oxide
- Third phase formation in the extraction of Th(NO3)4 by tri-2-methyl butyl phosphate from nitric acid media
- Solvent extraction behaviour of some fission product elements with N,N-dihexyl octanamide and tri-n-butyl phosphate under simulated PUREX process conditions
- Transport of uranium from nitric acid solution by non-dispersive solvent extraction using a hollow fibre contactor
- Fixation of some major fission products in NaZr2P3O12 ceramic employing microwave heating
- Synthesis, characterization and structural refinement of polycrystalline uranium substituted zirconolite CaZr0.9U0.1Ti2O7
- Effect of glass composition on diffusion of cesium in borosilicate glass
- Studies on diffusional mobility and selectivity of I− ion in plasticized anion-exchange membrane using radiotracer
- BEHSA grafted polymer for selective extraction of U(VI), Th(IV) and La(III) from acidic matrices and environmental samples – a green process
- Studies on the dissolution behaviour of ThO2 and (U,Th)O2 by a solid state reaction method
- Studies on some divalent metal α-isosaccharinic acid complexes
- Effect of humic acid on cesium sorption on silica colloids
- Preparation and preliminary biological evaluation of a 177Lu labeled nitroimidazole derivative for possible use in targeted tumor therapy
Artikel in diesem Heft
- Preface - Special Issue: NUCAR 2005
- Incomplete fusion mechanism in 16O + 93Nb reaction at 6 MeV/nucleon: Recoil range measurements
- Extraction of actinides using N, N, N′, N′-tetraoctyl diglycolamide (TODGA): a thermodynamic study
- Extraction of neptunium(IV) by a mixture of 3-phenyl-4-acetyl-5-isoxazolone and tri-n-octyl phosphine oxide
- Third phase formation in the extraction of Th(NO3)4 by tri-2-methyl butyl phosphate from nitric acid media
- Solvent extraction behaviour of some fission product elements with N,N-dihexyl octanamide and tri-n-butyl phosphate under simulated PUREX process conditions
- Transport of uranium from nitric acid solution by non-dispersive solvent extraction using a hollow fibre contactor
- Fixation of some major fission products in NaZr2P3O12 ceramic employing microwave heating
- Synthesis, characterization and structural refinement of polycrystalline uranium substituted zirconolite CaZr0.9U0.1Ti2O7
- Effect of glass composition on diffusion of cesium in borosilicate glass
- Studies on diffusional mobility and selectivity of I− ion in plasticized anion-exchange membrane using radiotracer
- BEHSA grafted polymer for selective extraction of U(VI), Th(IV) and La(III) from acidic matrices and environmental samples – a green process
- Studies on the dissolution behaviour of ThO2 and (U,Th)O2 by a solid state reaction method
- Studies on some divalent metal α-isosaccharinic acid complexes
- Effect of humic acid on cesium sorption on silica colloids
- Preparation and preliminary biological evaluation of a 177Lu labeled nitroimidazole derivative for possible use in targeted tumor therapy
