— α-NaCaAlF6 is prepared by solid state reaction as poor quality crystals. The structure is determined ab initio from conventional X-ray powder data. The cell is monoclinic, space group P21/c, Z = 8, with a = 8.7423(3) Å, b = 5.1927(2) Å, c = 20.3514(9) Å and β = 91.499(2)°. The final Rietveld refinement leads to RP = 10.6 % and RB = 5.2 %. The structure is built up from isolated AlF6 octahedra...

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...

We propose two improvements to the microstructural modeling in Rietveld refinement. The first is the model that yields the complete texture-weighted strain and stress tensors as a function of crystallite orientations, as well as the average values of macroscopic strain and stress tensors for all Laue classes. Implementation in the Rietveld refinement program can be made through the set of refin...

The procedure for the quantitative phase analysis using the whole-powder-pattern decomposition method has been applied to ten-component mixtures of synthesized ceramic materials and a five-component mixture of natural products. Average deviations of the calculated weight fractions of respective phases from those prepared in mixing were within 1 weight percent (wt.%), and they were smaller than ...

We report on the residual stresses in amorphous shape memory polymers reinforced with SiC particles. After 50% compression of the composite material at 25 °C, the SiC particles exhibit a compressive stress, which is almost completely released during heated recovery at 120 °C. The residual stresses in SiC hexagonal (6H) phase were estimated through the average change of the unit-cell volume. Lat...

PdZn catalysts have been proven to be a viable option to replace current Cu catalysts for methanol steam reforming. The change in selectivity to CO2 that makes this a possibility has been attributed to the formation of tetragonal β1-PdZn at treatment temperatures of 500 o C. Through the course of studying the phase evolution of the 1:1 PdZn, it was seen that an intermediate Pd2Zn phase formed a...

We have prepared polycrystalline samples of the trimer Ir oxide BaIrO3 with face-shared Ir3O12 trimers, and have investigated the origin of the phase transition at 182 K by measuring resistivity, thermopower, magnetization and synchrotron X-ray diffraction. We propose a possible electronic model and transition mechanism, starting from a localized electron picture on the basis of the Rietveld re...

Figure S1. Rietveld refinement patterns of PCN-888 using synchrotron PXRD data (λ = 0.72768Å): observed (blue), calculated (red), and difference (grey) profiles are shown; the tick marks below the curves indicate Bragg positions. The X-ray diffraction pattern between 1.1° and 4.2° is magnified in the inset. The full pattern shows a precise match between the experimental PXRD data and those simu...

This paper presents a method of reducing the X-ray diffraction data collection time, while maintaining high data quality, suitable for Rietveld refinement. The approach taken here is that phases in general show peak broadening as well as a loss of intensity with increasing 2-theta. Thus, by splitting the full analyzed 2-theta range into regions and adjusting the step-size and counting time to a...

The power of the state-of-the-art neutron powder diffractometer suite at the Institut Laue–Langevin for investigating the structure of nondeuterated materials is presented using gypsum, CaSO4 2H2O, as a reference material. It is shown that flexible modern neutron powder diffraction instruments at reactorbased sources can yield data with sufficient counting statistics above the incoherent scatte...