Preliminary Results From a Powder Diffraction Data Intensity Round-Robin

1987 ◽  
Vol 31 ◽  
pp. 309-315
Author(s):  
Walter N. Schreiner ◽  
Ron Jenkins
Keyword(s):  
Line Profile ◽  
Powder Diffraction ◽  
Computer Analysis ◽  
Diffraction Data ◽  
Cell Parameter ◽  
Round Robin ◽  
Measured Data ◽  
Powder Diffraction Data ◽  
X Ray ◽  
A Cell

For many years the International Centre for Diffraction Data has sponsored round robins covering various aspects of X-ray powder Diffraction with the objective of illuminating and understanding current practices and problems associated with, the analysis of diffraction data. As computer analysis of diffraction data becomes ever more sophisticated, analytic capabilities are extended and the performance, not only of the instrumentation must be checked, but also that of the software which converts the measured data into useful results. In recent years, therefore, we have personally participated in a cell parameter round-robin, a d-spacing round-robin, a peak hunting round-robin, and, most recently, the present intensity round-robin and a line profile round-robin. Still others are in progress or being planned.

Preparation and crystal structure of garnet-type calcium zirconium germanate Ca4ZrGe3O12

2016 ◽  
Vol 31 (4) ◽  
pp. 292-294 ◽  
Author(s):  
V. D. Zhuravlev ◽  
A. P. Tyutyunnik ◽  
N. I. Lobachevskaya
Keyword(s):  
Crystal Structure ◽  
Unit Cell Parameter ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Cell Parameter ◽  
Polycrystalline Sample ◽  
Structural Formula ◽  
Powder Diffraction Data ◽  
Structural Refinement ◽  
X Ray

A polycrystalline sample of Ca4ZrGe3O12 was synthesized using the nitrate–citrate method and heated at 850–1100 °C. Structural refinement based on X-ray powder diffraction data showed that the crystal structure is of the garnet type with a cubic unit-cell parameter [a = 12.71299(3) Å] and the space group Ia$\bar 3$d. The structural formula is presented as Ca3[CaZr]octa[Ge]tetraO12.

Structure and Magnetic Properties of (Cr,Ni)4-xCoxSi

2019 ◽  
Vol 289 ◽  
pp. 108-113
Author(s):  
Romana Iryna Martyniak ◽  
Nataliya Muts ◽  
Olga Sichevych ◽  
Horst Borrmann ◽  
Matej Bobnar ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Cell Parameter ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Pearson Symbol ◽  
Paramagnetic Behaviour

The crystal structure of the (Cr,Ni)4Si phase with and without Co was refined from X-ray powder diffraction data. The compound crystallises with an Au4Al-type structure (Pearson symbol cP20, space group P213): unit-cell parameter a = 0.611959(6) nm for the composition (Cr0.312Ni0.688)4Si, a = 0.612094(6) nm for (Cr0.375Ni0.625)4Si, and a = 0.612316(6) nm for (Cr0.337Co0.063Ni0.600)4Si. The magnetic susceptibility was measured in external fields up to 7 T at temperatures between 1.8 and 400 K. The three investigated samples exhibited paramagnetic behaviour described by the modified Curie-Weiss law: χ0 = 146∙10-6 emu g-at.-1, μeff = 0.21 μB/atom, θP = -13 K for (Cr0.312Ni0.688)4Si; χ0 = 158∙10-6 emu g-at.-1, μeff = 0.20 μB/atom, θP = -15 K for (Cr0.375Ni0.625)4Si; χ0 = 169∙10-6 emu g-at.-1, μeff = 0.18 μB/atom, θP = -52 K for (Cr0.337Co0.063Ni0.600)4Si.

Powder diffraction data of SmBa4Cu3O8.5+δ

1997 ◽  
Vol 12 (4) ◽  
pp. 242-244 ◽  
Author(s):  
Y. T. Zhu ◽  
P. S. Baldonado ◽  
E. J. Peterson ◽  
D. E. Peterson ◽  
F. M. Mueller
Keyword(s):  
Unit Cell Parameter ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Cell Parameter ◽  
Rietveld Analysis ◽  
Unit Cell ◽  
Oxygen Atmosphere ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Perovskite Unit Cell

Rietveld analysis of X-ray powder diffraction data was performed on SmBa4Cu3O8.5+δ, which was synthesized from precursors Sm2O3, BaO2, and CuO at 1000 °C in an oxygen atmosphere. SmBa4Cu3O8.5+δ has a cubic perovskite-related structure that is isostructural with YBa4Cu3O8.5+δ, and a doubled perovskite unit cell parameter of 8.177 90±0.000 04 Å.

Structure refinement and X-ray powder diffraction data for kalipyrochlore (K,Sr,Na,Ca,H2O)2−m(Nb,Ti)2−xO6−wY1−n, with (0

1995 ◽  
Vol 10 (3) ◽  
pp. 180-184 ◽  
Author(s):  
S. Philippo ◽  
J. Naud ◽  
J. P. Declercq ◽  
J. Feneau-Dupont
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Cell Parameter ◽  
Structure Refinement ◽  
Type Structure ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Pyrochlore Type ◽  
A Site

The kalipyrochlore (K,Sr,Na,Ca,H2O)2−m(Nb,Ti)2−xO6−wY1−n, with (0<m<0.8, x∼0.2, w = 0 and 0.2<n<1) from Lueshe, Zaire is a defect pyrochlore species whose A-site weakly depleted. The measured powder diffraction is presented with a calculated figure of merit F(30) = 74.7(0.010,39). The structure has been refined by single-crystal from X-ray diffraction data collected on a Huber four-circle diffractometer and by Rietveld analysis from X-ray powder diffraction data. The slightly weathered crystal (studied by single crystal) has a cubic pyrochlore-type structure with the same atomic positions and a unit-cell parameter a = 10.603(5) Å, space group (S.G.): Fd3m. The highly weathered crystal (studied by Rietveld) has the same cubic pyrochlore-type structure except for the oxygen position. The oxygen moved from the 48f position with x, y, z equal to 0.284, 0, 0 to x = 0.308(5), y = 0.024(6) and z = –0.028(9). The cell parameter is a = 10.569(6)±0.0007 Å. These modifications of positions induce a distortion of the A-site into an hexagonal bipyramid and an elongation of the B-site along the c axis of the octahedron.

X-Ray Diffraction Data for Lu(OH)3

1987 ◽  
Vol 2 (1) ◽  
pp. 39-40 ◽  
Author(s):  
D. F. Mullica ◽  
E. L. Sappenfield
Keyword(s):  
Powder Diffraction ◽  
Thermal Gravimetric Analysis ◽  
Diffraction Data ◽  
Cell Parameter ◽  
Gravimetric Analysis ◽  
Powder Diffraction Data ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Figures Of Merit

AbstractIndexed powder diffraction data for Lu(OH)3 are reported. The compound is cubic, Im3(No. 204), with a = 8.2221(3)Å, V = 555.84Å3, Z = 8, Dm = 5.36(4)Mg m−3 (Dx = 5.40Mg m−3). The refined cell parameter was determined by employing a Siemens Debye-Scherrer camera (Cu radiation, Ni filter). The indexed data were evaluated according to the quantitative figures of merit FN and M20 (F29 = 20(0.028,51) and M20 = 43.5). A thermal gravimetric analysis is presented. The JCPD S Diffraction File No. for Lu(OH)3 is 38–1500.

Powder diffraction of the cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ

2003 ◽  
Vol 18 (1) ◽  
pp. 56-59 ◽  
Author(s):  
Herman Koster ◽  
Fre´de´ric H. B. Mertins
Keyword(s):  
Unit Cell Parameter ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Cell Parameter ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray

X-ray powder diffraction data for Ba0.5Sr0.5Co0.8Fe0.2O3−δ are reported. The powder was prepared using a metal-EDTA complexing method. The XRD data could be fitted with a primitive cubic unit cell in space group Pm3m (No. 221). The Rietveld refined unit cell parameter is ac=0.398 30(3) nm with Z=1 and Dx=5.75 g/cm3.

Use of TALP with laboratory powder diffraction data from 2D detectors

2013 ◽  
Vol 28 (S2) ◽  
pp. S481-S490
Author(s):  
Oriol Vallcorba ◽  
Anna Crespi ◽  
Jordi Rius ◽  
Carles Miravitlles
Keyword(s):  
Organic Compounds ◽  
Structural Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Pattern ◽  
Experimental Setup ◽  
Intensity Data ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Molecular Compounds

The viability of the direct-space strategy TALP (Vallcorba et al., 2012b) to solve crystal structures of molecular compounds from laboratory powder diffraction data is shown. The procedure exploits the accurate metric refined from a ‘Bragg-Brentano’ powder pattern to extract later the intensity data from a second ‘texture-free’ powder pattern with the DAJUST software (Vallcorba et al., 2012a). The experimental setup for collecting this second pattern consists of a circularly collimated X-ray beam and a 2D detector. The sample is placed between two thin Mylar® foils, which reduces or even eliminates preferred orientation. With the combination of the DAJUST and TALP software a preliminary but rigorous structural study of organic compounds can be carried out at the laboratory level. In addition, the time-consuming filling of capillaries with diameters thinner than 0.3mm is avoided.

Solving a superstructure from two-wavelength x-ray powder diffraction data - a simulation

2003 ◽  
Vol 12 (3) ◽  
pp. 310-314
Author(s):  
Chen Jian-Rong ◽  
Gu Yuan-Xin ◽  
Fan Hai-Fu
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
X Ray

Crystallographic study of ternary ordered skutterudite IrGe1.5Se1.5

2010 ◽  
Vol 25 (3) ◽  
pp. 247-252 ◽  
Author(s):  
F. Laufek ◽  
J. Návrátil
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Crystallographic Data ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Crystallographic Study ◽  
Related Phase ◽  
The Ideal

The crystal structure of skutterudite-related phase IrGe1.5Se1.5 has been refined by the Rietveld method from laboratory X-ray powder diffraction data. Refined crystallographic data for IrGe1.5Se1.5 are a=12.0890(2) Å, c=14.8796(3) Å, V=1883.23(6) Å3, space group R3 (No. 148), Z=24, and Dc=8.87 g/cm3. Its crystal structure can be derived from the ideal skutterudite structure (CoAs3), where Se and Ge atoms are ordered in layers perpendicular to the [111] direction of the original skutterudite cell. Weak distortions of the anion and cation sublattices were also observed.

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