Results 241 to 250 of about 42,195 (291)

Rietveld refinement for CuInSe2 and CuIn3Se5

Journal of Alloys and Compounds, 2004
Rietveld refinements for copper indium selenides CuInSe2 and CuIn3Se5 and their mixture were performed using data collected at a Bragg–Brentano diffractometer. The values of lattice parameters, axial ratio and positional parameters are discussed and compared to available literature data for single crystals and polycrystals.
W Paszkowicz, R Lewandowska, R Bacewicz
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Rietveld refinement study of pyrite crystals

Journal of Alloys and Compounds, 2005
Abstract Rietveld refinement was performed for two samples prepared from natural pyrite (a polymorph of iron disulphide or iron persulphide, FeS 2 ) single crystals originating from Navajun (Spain) and from Ural Mts. (Russia). The present refinements provide the following crystallographic data: a  = 5.41784(2) and 5.41819(2) A, x  = 0.3848(1) and 0.
W. Paszkowicz, J.A. Leiro
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Profile shape functions in Rietveld refinements

Journal of Applied Crystallography, 1982
Reflection profile functions used or suggested for use in Rietveld refinements with fixed-angle or fixed-wavelength powder diffraction data, obtained with neutrons or with X-rays, are reviewed briefly. The fixed-wavelength X-ray case is considered in detail.
R. A. Young, D. B. Wiles
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Chapter 9. Rietveld Refinement

2008
A polycrystalline powder can be represented in reciprocal space as a set of nested spherical shells positioned with their centers at the origin1(Figure 9.1). These shells arise from the reciprocal lattice points from the myriad (e.g.
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Synthesis and rietveld refinement of MgO nanoparticles

AIP Conference Proceedings, 2020
Magnesium oxide (MgO) nanoparticles were synthesized using nitrate-citrate sol-gel route and the sample yield was annealed at 300°C, 450°C and 700°C for getting size distribution. Structural characterization was done by powder X-ray diffraction (XRD) measurements.
Himani Bhoi, Pragya Joshi, Khushboo Punia, Ganesh Lal, Sudhish Kumar   +4 more
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Application of Multidimensional Rietveld Refinement

We showcase a method development in neutron powder diffraction, primarily driven by the future time-of-flight diffractometer POWTEX, developed in collaboration with Forschungszentrum Jülich at FRM-II in Garching. Within the DAPHNE project, we are expanding these methods for wider applications, emphasizing sustainability.
Meinerzhagen, Yannick, Houben, Andreas, Dronskowski, Richard   +2 more
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X-ray Rietveld structure refinement of Sb3O6.5

Journal of Alloys and Compounds, 2010
Abstract The crystal structure of Sb 3 O 6.5 has been refined using the Rietveld analysis of X-ray powder diffraction data. The refinement procedure was stopped when the intensity residual R B  = 6.1% had been reached. Sb 3 O 6.5 crystallizes in a cubic structure of the defect pyrochlore type, space group Fd -3 m (No.
V.I. Sidey, P.M. Milyan, O.O. Semrad
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Mathematical aspects of Rietveld refinement

1993
Abstract The method of least squares is a powerful technique for estimating the values of the adjustable parameters in a model, M(x), that predicts the values of a set of observable quantities, y. One seeks the minimum, as a function of x, of the quadratic form.
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Rietveld refinement of incommensurate low tridymite

Zeitschrift für Kristallographie - Crystalline Materials, 2003
Abstract The incommensurate modification of SiO2 low-tridymite was refined in the 3 + 1 dimensional superspace group Cc(α0γ) 0 at 295 and 325 K from X-ray powder diffraction data. The displacive modulation mainly consists of tiltings of rigid SiO4/2 tetrahedra with the wave vector r = 0.656a* – 0.496c* (dimensions of the average cell: a =
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Strontium in the collinsite structure: Rietveld refinement

Crystallography Reports, 2003
The crystal structure of a strontium variety of a rare phosphate—mineral collinsite (Ca2 − x Srx)2Mg[PO4] · 2H2O was solved from powder X-ray diffraction data (λ CuK α radiation, Ni filter, 12.36° ≤ 2θ ≤ 100.00°, scan step 0.02°, exposure time per step 15 s) by the Rietveld method (R wp = 4.15%, R F = 1.03%, R B = 2.46%); a = 5.8219(1) A, b = 6.8319(2)
O. V. Yakubovich, Yu. K. Kabalov, P. G. Gavrilenko, R. P. Liferovich, W. Massa   +4 more
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