The crystal structure of La0.7Pr0.3Ba2Cu3Od ceramic compound

2002 ◽  
Vol 17 (1) ◽  
pp. 25-29 ◽  
Author(s):  
X. S. Wu ◽  
H. Sha ◽  
W. S. Tan ◽  
Tao Yu ◽  
A. Hu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Room Temperature ◽  
Total Content ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Orthorhombic System ◽  
X Ray ◽  
Ceramic Compound ◽  
Content Of Oxygen

The structure of new La0.7Pr0.3Ba2Cu3Oy (LPBCO) compound was obtained at room temperature from synchrotron radiation X-ray powder diffraction data and refined by Rietveld technique. LPBCO has an isotypical structure with YBa2Cu3Oy (YBCO). The crystal data are: La0.7Pr0.3Ba2Cu3O6.96, Mr=716.16, orthorhombic system, space group Pmmm, a=3.9147(1) Å, b=3.8672(1) Å, c=11.7033(2) Å, V=177.177(6) Å3, Z=1, Dx=6.714 g/cm3; the structure was refined with 35 parameters to Rwp=7.41%, Rp=5.32%, and Rexp=3.07% for 5001 step intensities. Moreover, the total content of oxygen in a unit cell is refined as 6.96, which is less than that of the calculated one. We attribute the superconductivity-depression to the increase of the valence of copper.

Crystal structure of Cu doped La0.67Ca0.33MnO3 by Rietveld refinement

2004 ◽  
Vol 19 (4) ◽  
pp. 329-332
Author(s):  
H. L. Cai ◽  
X. S. Wu ◽  
F. Z. Wang ◽  
A. Hu ◽  
S. S. Jiang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structural Changes ◽  
Rietveld Method ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Orthorhombic System ◽  
X Ray

The crystal structure of La0.67Ca0.33Mn0.80Cu0.20O3 (LCMCO) compound was determined from laboratory X-ray powder diffraction data and refined by the Rietveld method. LCMCO is isostructural with La0.67Ca0.33MnO3 (LCMO). The crystal data are: La0.64Ca0.36Mn0.82Cu0.18O3.01, Mr=843.80, orthorhombic system, space group Pnma, a=5.4364(1) Å, b=7.6725(2) Å, c=5.4452(1) Å, V=227.124(8)Å3, Z=4, Dx=6.168 g∕cm3. In comparing with the Cu-free compound, subtle structural changes such as bond lengths and bond angles found in the Cu-doped compound may be responsible for the larger effects on the transport and magnetic properties when Cu partially substitutes for Mn in CMCO.

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.

Structure determination and Rietveld refinement of Y0.8Ca0.2Ba1.8La0.2Cu3Oy

2001 ◽  
Vol 16 (4) ◽  
pp. 212-215 ◽  
Author(s):  
X. S. Wu ◽  
F. Z. Wang ◽  
S. S. Jiang
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Room Temperature ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Orthorhombic System ◽  
X Ray ◽  
Data Points ◽  
Stoichiometric Proportion

The structure of the new Y0.8Ca0.2Ba1.8La0.2Cu3Oy (YBLCO) compound was obtained at 298 K from X-ray powder diffraction data and refined by the Rietveld technique. YBLCO has a structure isotypical with YBa2Cu3Oy (YBCO) at room temperature. The crystal data are: Y0.81Ca0.19Ba1.8La0.2Cu3O7.08, Mw=657.69, orthorhombic system, space group Pmmm, a=3.8731(1) Å, b=3.8249(1) Å, c=11.6602(3) Å, V=172.740(13) Å3, Z=1, dx=6.325 g/cm3; the structure was refined with 37 parameters to Rwp=7.66%, Rp=5.86%, and Rexp=5.11% for 2001 data points. Moreover, the proportions of Ca and La were refined to be 0.19 and 0.2, in agreement with the stoichiometric proportion of 0.2.

Crystal structure of the anticancer drug carmustine determined by X-ray powder diffraction

2021 ◽  
pp. 1-3
Author(s):  
Carina Schlesinger ◽  
Edith Alig ◽  
Martin U. Schmidt
Keyword(s):  
Crystal Structure ◽  
Anticancer Drug ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Powder Diffraction Data ◽  
Orthorhombic Space Group ◽  
Commercial Sample ◽  
One Dimensional ◽  
X Ray ◽  
Hydrogen Bond Pattern

The structure of the anticancer drug carmustine (1,3-bis(2-chloroethyl)-1-nitrosourea, C5H9Cl2N3O2) was successfully determined from laboratory X-ray powder diffraction data recorded at 278 K and at 153 K. Carmustine crystallizes in the orthorhombic space group P212121 with Z = 4. The lattice parameters are a = 19.6935(2) Å, b = 9.8338(14) Å, c = 4.63542(6) Å, V = 897.71(2) ų at 153 K, and a = 19.8522(2) Å, b = 9.8843(15) Å, c = 4.69793(6) Å, V = 921.85(2) ų at 278 K. The Rietveld fits are very good, with low R-values and smooth difference curves of calculated and experimental powder data. The molecules form a one-dimensional hydrogen bond pattern. At room temperature, the investigated commercial sample of carmustine was amorphous.

Synthesis and structure of the ternary nitride Li6WN4

2005 ◽  
Vol 20 (1) ◽  
pp. 18-21 ◽  
Author(s):  
W. X. Yuan ◽  
J. W. Hu ◽  
Y. T. Song ◽  
W. J. Wang ◽  
Y. P. Xu
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Room Temperature ◽  
Powder Diffraction Data ◽  
High Quality ◽  
X Ray ◽  
Cell Parameters ◽  
Tetragonal System ◽  
Ternary Nitride ◽  
Stability Measurements

The ternary nitridotungstate Li6WN4 has been synthesized via the solid state reaction of lithium subnitride, Li3N, with W under nitrogen. High quality X-ray powder diffraction data were collected for the crystal-structure determination. Li6WN4 crystallizes in the tetragonal system, space group P42∕nmc, with cell parameters a=6.6759(3) Å and c=4.9280(3) Å, Z=2. Preliminary thermal stability measurements of Li6WN4 show that it is sensitive to moisture, even at room temperature, and decomposes at high temperatures below 1000 °C under flowing nitrogen.

Preparation and crystal structure of SbV1.50InIII0.50(PO4)3 and (SbV0.50InIII0.50)P2O7

2008 ◽  
Vol 23 (3) ◽  
pp. 232-240
Author(s):  
Abderrahim Aatiq ◽  
Rachid Bakri ◽  
Aaron Richard Sakulich
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Room Temperature ◽  
Rietveld Method ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Orthorhombic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Synthesis and structure of two phosphates belonging to the ternary Sb2O5–In2O3–P2O5 system are realized. Structures of SbV1.50InIII0.50(PO4)3 and (SbV0.50InIII0.50)P2O7 phases, obtained by solid state reaction in air at 950 °C, were determined at room temperature from X-ray powder diffraction using the Rietveld method. SbV1.50InIII0.50(PO4)3 have a monoclinic (space group P21/n) distortion of the Sc2(W O4)3-type framework. Its structure is constituted by corner-shared SbO6 or InO6 octahedra and PO4 tetrahedra. Monoclinic unit cell parameters are a=11.801(2) Å, b=8.623(1) Å, c=8.372(1) Å, and β=90.93(1)°. (Sb0.50In0.50)P2O7 is isotypic with (Sb0.50Fe0.50)P2O7 and crystallizes in orthorhombic system (space group Pna21) with a=7.9389(1) Å, b=16.0664(2) Å, and c=7.9777(1) Å. Its structure is built up from corner-shared SbO6 or InO6 octahedra and P2O7 groups (two group-types). Each P2O7 group shares its six vertices with three SbO6 and three InO6 octahedra, and each octahedron is connected to six P2O7 groups.

Metal Complexes of 1,3-Bis(Pyridin-2-yl)pyrazole: Spectral, Magnetic and Structural Studies

1995 ◽  
Vol 48 (6) ◽  
pp. 1071 ◽  
Author(s):  
AT Baker ◽  
DC Craig ◽  
G Dong ◽  
AD Rae
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Complex Cation ◽  
Tridentate Ligand ◽  
Structural Studies ◽  
Crystal Data ◽  
Octahedral Structure ◽  
Heterocyclic Ligands ◽  
X Ray ◽  
Donor Nitrogen

Bis(ligand)iron(II) and nickel(II) complexes of the asymmetric tridentate ligand 1,3-bis(pyridin-2-yl) pyrazole , L, have been prepared. The iron(II) complex, [FeL2] [PF6]2, is high-spin in the solid state over the temperature range 304-102 K, with a magnetic moment of 5.27 BM at room temperature. The crystal structure of bis (1,3-bis(pyridin-2-yl) pyrazole )iron(II) bis (hexafluorophosphate ) has been determined by single-crystal X-ray diffractometry. The compound crystallized as yellow prisms, with the structure being disordered in the tetragonal space group P421c with Z = 2. Crystal data a = b = 8.785(1) Ǻ, c = 19.804(6) Ǻ. The iron(II) centre is in an N6 environment, where the six donor nitrogen atoms are provided by the two tridentate heterocyclic ligands. The complex cation has an approximately octahedral structure exhibiting tetragonal compression. The observed Fe-N(pyridine) and Fe-N( pyrazole ) distances are 2.308(4) and 2.019(7) Ǻ respectively, with the Fe-N(pyridine) distance being the longest observed to date.

Rietveld powder structure refinement of Na2Al2Ti6O16; Comparison of synchrotron radiation and conventional x-ray tube datasets

1990 ◽  
Vol 5 (7) ◽  
pp. 1538-1543 ◽  
Author(s):  
H. Toraya ◽  
N. Masciocchi ◽  
W. Parrish
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Chemical Analysis ◽  
Rietveld Method ◽  
Structure Refinement ◽  
Site Occupancy ◽  
Partial Ordering ◽  
Crystal Data ◽  
X Ray ◽  
Octahedral Sites

The crystal structure of Na2Al2Ti6O16 was refined by the Rietveld method using synchrotron radiation and conventional x-ray powder data, and the agreement factors were Rp = 3.35%, Rwp = 4.30%, and RBragg = 6.39% for synchrotron data. The formula based on the chemical analysis and 16 O atoms is Na1.97Al1.82Ti6.15O16. The crystal data are monoclinic, C2/m, a = 12.1239(3) Å, b = 3.7749(1) Å, c = 6.4180(2) Å, β = 107.59(1)°, V = 280.00(4) Å3, Z = 1, and Dx = 3.82 g cm−3. The site occupancy refinement showed a partial ordering of Al3+ and Ti4+ ions in the two-crystallographically independent octahedral sites.

X-ray powder diffraction data and structural study of Cd4GeSe6

1998 ◽  
Vol 13 (4) ◽  
pp. 202-209 ◽  
Author(s):  
J. A. Henao ◽  
J. M. Delgado ◽  
M. Quintero
Keyword(s):  
Crystal Structure ◽  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Rietveld Method ◽  
Monoclinic Space Group ◽  
Temperature Phase ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Semiconducting Material

The X-ray powder diffraction pattern of the room temperature phase of Cd4GeSe6, a II4 □ IV VI6 semiconducting material, has been recorded and evaluated. This material crystallizes in the monoclinic space group Cc [No. 9] with a=12.847(3), b=7.407(2), c=12.854(2) Å, β=109.82(1)°, and Z=4. The powder diffraction pattern was also used to refine the crystal structure of this material employing the Rietveld method. The refinement of 56 parameters led to RWP=13.2%, RP=9.95% for 3751 step intensities and RB=7.05% and RF=5.20% for 833 reflections. Cd4GeSe6 can be considered a defect “adamantane-structure” material with a sphalerite-related superstructure.

Powder X-ray diffraction of levothyroxine sodium pentahydrate, C15H10I4NNaO4(H2O)5

2015 ◽  
Vol 30 (4) ◽  
pp. 370-371
Author(s):  
J.A. Kaduk ◽  
K. Zhong ◽  
T.N. Blanton ◽  
S. Gates ◽  
T.G. Fawcett
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Room Temperature ◽  
Levothyroxine Sodium ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Synchrotron Powder Diffraction

The room-temperature crystal structure of levothyroxine sodium pentahydrate has been refined using synchrotron powder diffraction data. The compound crystallizes in space group P1 (#1) with a = 8.2489(4), b = 9.4868(5), c = 15.8298(6) Å, α = 84.1387(4), β = 83.1560(3), γ = 85.0482(3) deg, V = 1220.071(9) Å3, and Z = 2. Hydrogen atoms (missing from the previously-reported structure) were included.

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