The paper addresses requirements for achieving Rietveld phase composition analysis (PCA) accuracy in the vicinity of 1% by weight with particular reference to scale factor precision. It is proposed from a statistical analysis that the target for scale factor estimated standard deviation (esd) should be in the vicinity of 0.2% relative, with additional targets being assumed for the ZMV factors, ...

The new crystal structure of 5,6-dibromoacenaphthene has been successfully determined from X-ray powder diffraction data with monoclinic crystals, P21/n, a = 7.88(1) Å, b = 11.64(1) Å, c = 11.62(1) Å, β =107.09(9)°, V = 1019.9(1) Å and Z = 4. Individual reflection intensities were extracted by means of Le Bail’s method. The molecular structure of 1 was solved by direct methods and refined using...

We optimized synthesis conditions of blue-emitting CaMgSi2O6:Eu 2+ (CMS:Eu) with conventional solid-state reaction and successfully determined structure parameters by Rietveld refinement method with neutron powder diffraction data. The final weighted R-factor Rwp was 6.42% and the goodness-of-fit indicator S ( Rwp/Re) was 1.34. The refined lattice parameters of CMS:Eu were a 9.7472(3) Å, b 8.93...

X-ray powder diffractometry/Rietveld refinement was employed to estimate the purity of several chrysotile powders for calibrating standards. α-Corundum powder was mixed into each chrysotile sample as an internal standard. X-ray diffractometry was performed on these mixtures, and the mass fractions of amorphous and impurity phase content were calculated using Rietveld refinement. The chrysotile ...

In this article the authors aim to offer some practical advice for phoneticians being confronted with a voice parade request for the first time, by providing a detailed description of a parade carried out successfully in the UK. The methodology used in this parade is based on a number of studies on earwitnesses carried out since the 1990s. However, it primarily builds on the work by Nolan [5] f...

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...

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...

This study examined the local structural properties of CuI at low temperatures of 10-300 K by x-ray diffraction (XRD) and extended x-ray absorption fine structure (EXAFS) measurements at the Cu K edge. The XRD data were refined using two models, split (distorted zinc-blende structure) and non-split (zinc-blende structure), using a conventional Rietveld refinement combined with a maximum entropy...

-A structure refinement of kaolinite made using the Rietveld neutron profile refinement technique has given non-hydrogen atom positions which were not significantly different from those given by B. B. Zvyagin in i960. All of the hydrogen atoms have been located; the three inner-surface hydrogen atoms are involved in interlayer hydrogen bonds with lengths of 2.95(4), 2.95(4), and 3.06(4) ]k with...