Synthesis and Characterization of Ba2Cu3PrO7−x

1987 ◽  
Vol 99 ◽  
Author(s):  
J. Amador ◽  
C. Cascales ◽  
I. Rasines
Keyword(s):  
Least Squares ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Least Squares Method ◽  
Structural Data ◽  
Synthesis And Characterization ◽  
Powder Diffraction Data ◽  
Interatomic Distances ◽  
X Ray

ABSTRACTPolycrystalline black coloured Ba2Cu3PrO7−x is prepared from a mixture of analytical grade BaO2, CuO, Cu metal, and Pr 2O3 (2 : 2 : 1 : 0.5), which are ground, pelletized, and heated in evacuated quartz ampoules at 1273 K for 4 days, and then slowly cooled.X-ray powder diffraction data show that Ba2Cu3PrO7−x is orthorhombic, a = 3.823(2), b = 3.877(2), c= 11.793(5) Å, space group Pmmm (no. 47), Z = 1. The structure of Ba2Cu3PrO7−x is refined from 37 reflections by using a least-squares method up to Rc = 0.044 and Rw = 0.041. Structural data and main interatomic distances are given.

scholarly journals Powder X-ray characterization of djenkolic acid

2001 ◽  
Vol 16 (1) ◽  
pp. 46-47
Author(s):  
Petr Melnikov ◽  
Alexandre Cuin ◽  
Pedro P. Corbi ◽  
Maurício Cavicchioli ◽  
Antonio C. Massabni
Keyword(s):  
Amino Acid ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Natural Amino Acid ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Cell Parameters ◽  
Orthorhombic Cell ◽  
Djenkolic Acid

X-ray powder diffraction data for the orthorhombic natural amino acid djenkolic acid, C7H14N2O4S2, is described in this paper. The orthorhombic cell parameters are: a=8.12 Å, b=12.16 Å, and c=5.38 Å

Refinement of Structural Parameters for Polycrystalline CdSb2O6: A Comparison of Two Methods

1988 ◽  
Vol 3 (4) ◽  
pp. 219-221 ◽  
Author(s):  
A. Castro ◽  
I. Rasines ◽  
M.C. Sánchez-Martos ◽  
P. García-Casado
Keyword(s):  
Solid State ◽  
Least Squares ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
Structural Parameters ◽  
Optimization Technique ◽  
Powder Diffraction Data ◽  
Crystalline Powder ◽  
X Ray

AbstractTrigonal CdSb2O6, prepared as a very crystalline powder by solid state reaction of CdO and Sb2O3, is isostructural with PbSb2O6 Space Group (S.G.) P31m (162), with a = 5.2399(2), c = 4.8045(4) Å, Z = 1 and Dc = 6.57 Mg.m−3. For the refinement of structural parameters from X-ray powder diffraction data two different methods have been employed and compared, both leading to very similar results. The refinements converged to RI = 0.025 using 35 intensities in the incremental optimization technique and to RF = 0.038, RW = 0.033 from 161 reflections in the least-squares refinement.

A Modulation Wave Approach to the Structural Characterization of Three New Cristobalite-Related Sodium Magnesiosilicates

1997 ◽  
Vol 53 (2) ◽  
pp. 203-220 ◽  
Author(s):  
R. L. Withers ◽  
C. Lobo ◽  
J. G. Thompson ◽  
S. Schmid ◽  
R. Stranger
Keyword(s):  
Powder Diffraction ◽  
Structural Characterization ◽  
Diffraction Data ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Modulation Wave ◽  
Wave Approach ◽  
The Ideal

The crystal structures of three new cristobalite-related sodium magnesiosilicates [Na2MgSiO4, M r = 162.37, orthorhombic, Pna21, a = 10.835 (5), b = 5.279 (12), c = 7.067 (8) Å, D x = 2.668 g cm−3, Z = 4, Cu Kα, λ = 1.5418 Å, μ = 75.96 cm−l, F(000) = 319.87; Na1.74Mg0.79Al0.15Si1.06O4, M r = 157.02, orthorhombic, Pbca, a = 10.487 (7), b = 14.351 (4), c = 5.243 (6) Å, D x = 2.643 g cm−3, Z = 8, Cu Kα, λ = 1.5418 Å, μ = 76.70 cm−l, F(000) = 619.04; Na1.8Mg0.9Si1.1O4, M r = 158.15, tetragonal, P41212, a = 5.330 (6), c = 7.086 (5) Å, D x = 2.609 g cm−3, Z = 2, Cu Kα, λ= 1.5418 Å, μ = 75.44 cm−l, F(000) = 155.94] are determined by Rietveld refinement from X-ray powder diffraction data. Plausible starting models were derived from a modulation wave approach based on the ideal C9 structure type and assuming regular SiO4 and MgO4 tetrahedra.

Powder Diffraction Data Correction: Single-Crystal Standards and Fourier Asymmetric Component Stripping

1991 ◽  
Vol 35 (A) ◽  
pp. 353-358 ◽  
Author(s):  
Frank E. Briden ◽  
Richard B. Snoddy
Keyword(s):  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Lanthanum Hexaboride ◽  
Degree Of Crystallinity ◽  
Peak Width ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Asymmetric Component

The need for reliable standards for the characterization of x-ray powder diffraction (XRD) instruments has been well documented. As a result of the round robin study, of various candidate standard materials, described by Fawcett et al., the National Institute of Science and Technology has made the SRM-660, lanthanum hexaboride, XRD peak width standard available. It has been normal practice to use powder sample standards for XRD powder diffraction studies. Powder standards have been justified on the principle that standards should be as much as possible like the unknowns to be analyzed; however, standards must be quite different from the unknowns because their peak profiles must be as narrow as possible for deconvolution from sample peak profiles. It would seem most advantageous to use standards of the highest degree of crystallinity so that they would be useful over the maximum number of applications. Single crystals, with their extremely high crystallinity, offer that advantage.

Synthesis and X-ray powder diffraction study of the elpasolite Cs2NaCeCl6

1995 ◽  
Vol 10 (4) ◽  
pp. 241-242 ◽  
Author(s):  
R. Acevedo ◽  
V. Poblete
Keyword(s):  
Diffraction Study ◽  
Powder Diffraction ◽  
Structural Characterization ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray

The synthesis at 850 °C and the structural characterization of the elpasolite structure compound Cs2NaCeCl6 is reported space group Fm3m, a = 10.943(2) Å, V = 1310.4 (Å)3, Z = 4, M = 641.64, Dx = 3.252, and Dexp = 3.21. Powder diffraction data from a Rietveld structure refinement, are reported.

Structural characterization of form I of anhydrous rifampicin

CrystEngComm ◽  
2014 ◽  
Vol 16 (36) ◽  
pp. 8555-8562 ◽  
Author(s):  
Amanda Laura Ibiapino ◽  
Rafael Cardoso Seiceira ◽  
Altivo Pitaluga ◽  
Antonio Carlos Trindade ◽  
Fabio Furlan Ferreira
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Structural Characterization ◽  
Diffraction Data ◽  
Crystal Morphology ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Good Agreement

Crystal structure determination of form I of anhydrous rifampicin by X-ray powder diffraction data. Crystal morphology prediction revealed a good agreement with the images of the crystals.

Phosphorus: New in situ powder data from large-volume apparatus

2003 ◽  
Vol 18 (2) ◽  
pp. 155-158 ◽  
Author(s):  
Wilson A. Crichton ◽  
Mohamed Mezouar ◽  
Giulio Monaco ◽  
Sara Falconi
Keyword(s):  
Least Squares ◽  
Powder Diffraction ◽  
Large Volume ◽  
Diffraction Data ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Synthesis Conditions

Improved X-ray powder diffraction data for orthorhombic phosphorus, S.G. C mca (64) obtained in situ at synthesis conditions of 1.2 GPa and 1100 K, are described. Representative, as synthesized, data include 2.552X, 3.3204, 2.5953, 5.1912, 1.6302, for least-squares unit-cell a=3.3182(6) Å, b=10.3744(18) Å and c=4.3227(9) Å. As an illustration of the quality of the data, the structure was solved from powder XRD and Rietveld refined to give a=3.3199(2) Å, b= 10.3678(4) Å, c=4.3154(2)Å, and V=148.535(12) Å3 with the P atom on 8f (1/2, y,z) with y=0.1044(22) and z=0.9179(7).

PREPARATION AND CHARACTERIZATION OF UNUSUAL LEVITATION Tl-Ba-Ca-Cu-O SAMPLES

1989 ◽  
Vol 03 (03) ◽  
pp. 249-255 ◽  
Author(s):  
Z.Z. SHENG ◽  
Y.H. LIU ◽  
X. FEI ◽  
L. SHENG ◽  
C. DONG ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Preparation Procedure ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Electronic And Magnetic Properties

A preparation procedure for the Tl-Ba-Ca-Cu-O superconducting samples which can be levitated above or beneath a magnet is described. X-ray powder diffraction data for these samples are presented and discussed. Their electronic and magnetic properties are presented. The explanation for the unusual levitation is briefly discussed.

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