Rietveld Refinement of the BaTiO3 from X-Ray Powder Diffraction

2009 ◽  
Vol 79-82 ◽  
pp. 593-596
Author(s):  
Feng Sun ◽  
Yan Sheng Yin
Keyword(s):  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Structural Parameters ◽  
Ferroelectric Ceramic ◽  
Powder Diffraction Data ◽  
Ceramic Powders ◽  
Space Group ◽  
X Ray

The ferroelectric ceramic BaTiO3 was synthesized at 1000 °C for 5 h. The structure of the system under study was refined on the basis of X-ray powder diffraction data using the Rietveld method. The system crystallizes in the space group P4mm（99）. The refinement of instrumental and structural parameters led to reliable values for the Rp, Rwp and Rexp.We use the TOPAS software of Bruker AXS to refine this ceramic powders and show its conformation

Rietveld refinement of the crystal structure of α-CoSO4

1993 ◽  
Vol 8 (1) ◽  
pp. 54-56 ◽  
Author(s):  
Peter C. Burns ◽  
Frank C. Hawthorne
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

The crystal structure of α-CoSO4 has been refined by the Rietveld method from X-ray powder diffraction data. The structure is orthorhombic, space group Pnma, a = 8.6127(4), b = 6.7058(3), c = 4.7399(2) Å, V = 273.75(3) Å3. Final RB = 2.41%, RP = 5.24%, RWP=6.66%, RWP (expected) =5.74% (WP =weighted profile). The structure consists of edge-sharing octahedral chains parallel to [010] interconnected by SO4 tetrahedra.

Crystal Structure of the New Compound TbCo0.67Ga1.33

2015 ◽  
Vol 1089 ◽  
pp. 102-106
Author(s):  
Liu Qing Liang ◽  
Wen Jun Shen ◽  
Ling Min Zeng ◽  
Cai Min Huang
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Ternary Compound ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray

A new ternary compound TbCo0.67Ga1.33 was discovered and studied by means of X-ray powder diffraction technique. The crystal structure of the new compound was refined by using Rietveld method from X-ray powder diffraction data. This compound crystallizes in the orthorhombic with the CeCu2 structure type( space group Imma, a = 0.43384(6) nm, b = 0.70193(1) nm, c = 0.75617(1) nm, Z = 4, and Dcalc = 8.512 g/cm3 ). The Rietveld refinement results were Rp = 0.0996, Rwp = 0.1277.

Rietveld refinement of the crystal structures of hexagonal Y6Cr4+xAl43−x (x=2.57) and tetragonal YCr4−xAl8+x (x=1.22)

1995 ◽  
Vol 10 (2) ◽  
pp. 86-90 ◽  
Author(s):  
R. Černý ◽  
K. Yvon ◽  
T. I. Yanson ◽  
M. B. Manyako ◽  
O. I. Bodak
Keyword(s):  
Crystal Structures ◽  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray

Y6Cr4+xAl43−x (x = 2.57); space group P63/mcm, a = 10.8601(1) Å, c = 17.6783(3) Å, V= 1805.7(1) Å3, Z=2; isostructural to Yb6Cr4+xAl43−x, (x=1.76) with two aluminium sites partially occupied by chromium (44% and 27% Cr). YCr4−xAl8+x (x=1.22); space group I4/mmm, a = 9.0299(2) Å, c = 5.1208(2) Å, V=417.55(3) Å3, Z=2, disordered variant of CeMn4Al8 with one chromium site (8f) partially occupied by aluminium (33% Al); X-ray powder diffraction data were collected on a well-crystallized multiphase sample containing 43 wt.% of Y6Cr4+xAl43−x, 27 wt.% of Y2Cr8−xAl16+x, 16 wt.% of Al, 13 wt.% of YAl3, and traces of Y2O3. Structure refinement converged at Rwp = 2.0% and RB = 3.5, 3.6% resp. for a total of 78 parameters and 1190 reflections.

X-ray powder diffraction data and Rietveld refinement for a new iodate: (LiFe1/3)(IO3)2

2002 ◽  
Vol 17 (2) ◽  
pp. 132-134
Author(s):  
Y. C. Lan ◽  
X. L. Chen ◽  
Z. Tao ◽  
A. Y. Xie ◽  
P. Z. Jiang ◽  
...  
Keyword(s):  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Hexagonal Structure ◽  
Lattice Parameters ◽  
Powder Diffraction Data ◽  
Cation Site ◽  
Space Group ◽  
X Ray

The structure of a new iodate, (LiFe1/3)(IO3)2, has been determined. The new compound has a hexagonal structure with the lattice parameters a=5.4632(2) Å, c=5.0895(6) Å, Z=1. The density is 4.70 g cm−3. Rietveld refinement confirms that the compound has a space group of P63 (173). Fe and Li atoms randomly distribute on the 2a cation site.

scholarly journals Rietveld refinement guidelines

1999 ◽  
Vol 32 (1) ◽  
pp. 36-50 ◽  
Author(s):  
L. B. McCusker ◽  
R. B. Von Dreele ◽  
D. E. Cox ◽  
D. Louër ◽  
P. Scardi
Keyword(s):  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Shape Function ◽  
Structural Parameters ◽  
Structure Refinement ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Radiation Sources ◽  
Common Problems

A set of general guidelines for structure refinement using the Rietveld (whole-profile) method has been formulated by the International Union of Crystallography Commission on Powder Diffraction. The practical rather than the theoretical aspects of each step in a typical Rietveld refinement are discussed with a view to guiding newcomers in the field. The focus is on X-ray powder diffraction data collected on a laboratory instrument, but features specific to data from neutron (both constant-wavelength and time-of-flight) and synchrotron radiation sources are also addressed. The topics covered include (i) data collection, (ii) background contribution, (iii) peak-shape function, (iv) refinement of profile parameters, (v) Fourier analysis with powder diffraction data, (vi) refinement of structural parameters, (vii) use of geometric restraints, (viii) calculation of e.s.d.'s, (ix) interpretation ofRvalues and (x) some common problems and possible solutions.

Powder diffraction data and Rietveld refinement of metastable t-ZrO2 at low temperature

1997 ◽  
Vol 12 (2) ◽  
pp. 96-98 ◽  
Author(s):  
J. Málek ◽  
L. Beneš ◽  
T. Mitsuhashi
Keyword(s):  
Low Temperature ◽  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

Indexed X-ray powder diffraction data are reported for the low temperature tetragonal ZrO2 obtained by crystallization of zirconia gel. The structure was refined by the Rietveld technique on the basis of space group P42/nmc. Refined unit cell dimensions are a = 3.5984(5) Å, c = 5.152(1) Å, V = 66.71 Å3, Dx=6.135 g/cm3, F18=62 (0.012, 24), RP=8.99, Rwp=11.48, RB=3.13.

Crystallographic study of PtCl2(C2H3O2)2(C6H13N)(NH3) by Rietveld refinement

2003 ◽  
Vol 18 (2) ◽  
pp. 140-143 ◽  
Author(s):  
Lingmin Zeng ◽  
Liangwei Chen ◽  
Shaoping Pu ◽  
Yikun Yang ◽  
Wenggui Gao ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Anticancer Drug ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Crystallographic Study

X-ray powder diffraction data for the anticancer drug PtCl2(C2H3O2)2(C6H13N)(NH3) are reported. The crystal structure of PtCl2(C2H3O2)2(C6H13N)(NH3) obtained from a Rietveld refinement are: space group P21/a, a=13.547(2) Å, b=8.260(1) Å, c=14.638(3) Å, β=110.429(2)°, V=1534.96 Å3, Z=4 and Dcalc.=2.068 Mg/m3.

Chiral Molecular Alloys: Patterson-Search Structure Determination of L-Carvone and DL-Carvone from X-ray Powder Diffraction Data at 218 K

1997 ◽  
Vol 53 (4) ◽  
pp. 702-707 ◽  
Author(s):  
J. Sañé ◽  
J. Ruis ◽  
T. Calvet ◽  
M. A. Cuevas-Diarte
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Crystal Formation ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Positional Disorder ◽  
Search Structure ◽  
Patterson Search

The crystal structures of pure L-carvone [(R)-(−)-2-methyl-5-(1-methylethenyl)-2-cyclohexen-1-one, C10H14O] and the equimolar mixture DL-carvone (RS) have been determined by Patterson-search methods at low resolution from laboratory X-ray powder diffraction data (218 K). Crystal data: (L) a = 6.8576 (3), b = 6.8831 (5), c = 19.988 (2) Å, P212121 space group, Z = 4; (DL) a = 6.9744 (3), b = 6.8094 (6), c = 20.038 (7) Å, Pcmn space group, Z = 4. The L-carvone structure has been refined by the Rietveld method as a rigid body, allowing the rotation of the isopropenyl group (R\rho, = 0.030 and R wp = 0.043). Although the structure of DL-carvone could be unambiguously established, the Rietveld refinement was not possible due to the existence of preferred orientation in the sample and the difficulty in modelling the disorder. The molecular packing is essentialy the same for both compounds and can be explained as a stacking of two different molecular layers in the [001] direction. In each layer the molecules are placed with their long axis perpendicular to the layer plane, in a head-to-tail manner. The great similarity between the molecular shapes of L and D enantiomers favours the positional disorder in DL-carvone. This result confirms the mixed crystal formation for the chiral carvone system as proposed in recent thermodynamic studies. The DL-carvone crystal must be considered as a pseudo-racemate, since both enantiomers are randomly distributed over all the lattice sites.

Crystal and X-ray powder diffraction data for orthorhombic BaNd2Mn2O7 phase

1997 ◽  
Vol 12 (2) ◽  
pp. 103-105 ◽  
Author(s):  
Shunkichi Ueno ◽  
Naoki Kamegashira
Keyword(s):  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Lattice Parameters ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray

A Rietveld refinement of X-ray powder diffraction data for orthorhombic BaNd2Mn2O7 is reported. The refined lattice parameters were a=0.5517(5), b=0.5482(3), and c=2.0585(7) nm with space group Fmmm (No. 69).

Rietveld refinement of the crystal structure of γ-Mo4O11

1999 ◽  
Vol 14 (4) ◽  
pp. 284-288 ◽  
Author(s):  
Hoong-Kun Fun ◽  
Ping Yang ◽  
Minoru Sasaki ◽  
Masasi Inoue ◽  
Hideoki Kadomatsu
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Room Temperature ◽  
Rietveld Analysis ◽  
Powder Diffraction Data ◽  
Orthorhombic System ◽  
Space Group ◽  
X Ray

The crystal structure of γ-Mo4O11 was obtained at room temperature (296 K) by Rietveld analysis with X-ray powder diffraction data. The crystal belongs to orthorhombic system, space group: Pna21, Z=4, Mr=559.753 (Atomic weights 1977), Dx=4.1228 g/cm3, F(000)=1024.0, μ=451.293 cm−1 (Int. Tab. Vol. C, Table 4.2.4.2, p. 193, λ=1.540 60 Å), a=24.4756(5) Å, b=6.7516(1) Å, c=5.4572(1) Å, and V=901.80(3) Å3. The structure was refined to Rwp=5.60%, Rp=4.27%, Rb=3.36%, and Rf=2.74% for 65 parameters with 3541 step intensities and 3055 peaks. Goodness of the fit S=3.35.

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