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. Na2HfS...

The Rietveld method of structure refinement with powder diffraction patterns was originally devised for the analysis of fixed-wavelength (angle-dispersive) neuron data [1] [2] but now constitutes a major breakthrough for the usefulness of X-ray powder data [3]. This powerful method has greatly extended the amount of structural detail which can be obtained routinely from powder diffraction patte...

TiO2 nanoparticles with attractive physicochemical properties have synthesized by means of the sol-gel method and acid hydrolysis. The obtained nanoparticles have characterized by the XRD-Rietveld refinement, BET and TEM techniques, and tested in the photodecomposition of acetaldehyde. The degree of decomposition of acetaldehyde by the sol-gel TiO2 nanoparticles was directly proportional to the...

The structural characterization of the new iron-zinc hepta-borate bromide with composition Fe(1.59)Zn(1.41)B(7)O(13)Br, prepared by chemical transport is reported. A rigid-body model with constrained generalized coordinates was defined in order to hold the positions of the B atoms at reasonable inter-atomic distances that typically would reach unacceptable values because of the weak scattering ...

Current study represents the effect of the size and synthesis method on the cation distribution of cobalt ferrite nanoparticles and on the magnetic properties. The nanoferrites have been synthesized through sol-gel auto-combustion method using metal nitrates as precursor and citrate as fuel. In order to obtain the fine and agglomerated-free particles, we have used salt-assisted combustion react...