Crystal structure of Na2HfSi2O7 by Rietveld refinement
نویسندگان
چکیده
The structure of triclinic disodium hafnium disilicate, Na2HfSi2O7, has been determined by laboratory powder X-ray diffraction and refined by the Rietveld refinement. The structure is a framework made of alternate layers of HfO6 octa-hedra and SiO4 tetra-hedra linked by common O atoms. Sodium atoms are located in the voids of the framework, aligned into tunnels along the [010] direction. Na2HfSi2O7 is isostructural with the parakeldyshite Na2ZrSi2O7 phase.
منابع مشابه
Crystal Chemistry of Immobilization of tetravalent Ce and Se in ceramic matrix of sodium zirconium phosphates
The safe and effective management of radioactive waste has been given utmost importance from the very inception of nuclear industry in India and it covers the entire range of activities from handling, treatment, conditioning, transport, storage and finally disposal. Radioactive waste is generated at various stages of the nuclear fuel cycle, which includes the mining and milling of uranium ore, ...
متن کاملStructure of Pigment Yellow 181 dimethylsulfoxide N-methyl-2-pyrrolidone (1:1:1) solvate from XRPD + DFT-D
With only a 2.6 Å resolution laboratory powder diffraction pattern of the θ phase of Pigment Yellow 181 (P.Y. 181) available, crystal-structure solution and Rietveld refinement proved challenging; especially when the crystal structure was shown to be a triclinic dimethylsulfoxide N-methyl-2-pyrrolidone (1:1:1) solvate. The crystal structure, which in principle has 28 possible degrees of freedom...
متن کاملMorphological and Crystallographic Characterization of Nanoparticles by Granulometry Image Analysis and Rietveld Refinement Methods
The particle size distribution of the resultant cobalt ferrite samples was determined from Scanning Electron Microscopy (SEM) images using the granulometry image analysis method. Results showed the nanosized particles of the samples. The X-Ray Diffraction (XRD) patterns of samples were also analyzed by Rietveld refinement method. The results indicated that the precipitated sample at 95 <sup...
متن کاملRietveld Refinement with Xrd and Nd: Analysis of Metastable Qandilite-like Structures
Binary oxides of Mg and Ti were prepared by the sol-gel technique in various Mg/Ti atomic ratios, r. Metastable phases, produced between 873 and 973 K from xerogels with Mg/Ti atomic ratios in the range ~1.1 < r ≤ 2, were studied by XRD and ND. XRD analysis showed crystal structures similar to that of Mg2TiO4 (qandilite), an inverse spinel of cubic structure. The composition range where this oc...
متن کاملSynthesis and Rietveld crystal structure refinement of mackinawite, tetragonal FeS
Mackinawite,tetragonal FeS, has been synthesised by reacting iron with Na2S solutions. A Rietveld structure refinement of X-ray powder diffractipn data, recorded using X-rays monochromated from synchrotron radiationwith a wavelength of 0.6023 A, has been performed. The structure has been refined in the tetragonal sJ'.!lcegroup, P4/nmm, and has the following cell parameters: a = 3.6735(4), c = 5...
متن کامل