Synchrotron X-ray diffraction study of double perovskites Sr2RNbO6 (R = Sm, Gd, Dy, Ho, Y, Tm, and Lu)

A series of double-perovskite oxides, Sr2RNbO6 (R = Sm, Gd, Dy, Ho, Y, Tm, and Lu) were prepared and their crystal structure and powder diffraction reference patterns were determined using the Rietveld analysis technique. The crystal structure of each of the Sr2RNbO6 phase is reported in this paper. The R = Gd, Ho, and Lu samples were studied using synchrotron radiation, while R = Sm, Dy, Y, and Tm samples were studied using laboratory X-ray diffraction. Members of Sr2RNbO6 are monoclinic with a space group of P21/n and are isostructural with each other. Following the trend of “lanthanide contraction”, from R = Sm to Lu, the lattice parameters “a” of these compounds decreases from 5.84672(10) to 5.78100(3) Å, b from 5.93192(13) to 5.80977(3) Å, c from 8.3142(2) to 8.18957(5) Å, and V decreases from 288.355(11) to 275.057(2) Å3. In this double-perovskite series, the R3+ and Nb5+ ions are structurally ordered. The average Nb–O bond length is nearly constant, while the average R–O bond length decreases with the decreasing ionic radius of R3+. Powder diffraction patterns for these compounds have been submitted to the Powder Diffraction File (PDF).

Download Full-text

Crystal structures and reference X-ray powder diffraction patterns of Sr4−xCaxPb2O8 (x=1,2,3)

Powder Diffraction ◽

10.1017/s0885715600010162 ◽

1998 ◽

Vol 13 (4) ◽

pp. 232-240 ◽

Cited By ~ 1

Author(s):

W. Wong-Ng ◽

J. A. Kaduk ◽

W. Greenwood

Keyword(s):

Crystal Structure ◽

Solid Solution ◽

Crystal Structures ◽

Powder Diffraction ◽

Alkaline Earth ◽

Lattice Parameters ◽

X Ray Diffraction ◽

Powder Diffraction File ◽

X Ray ◽

Diffraction Patterns

The crystal structure of the solid solution alkaline earth plumbate phase Sr4−xCaxPb2O8 was investigated using the X-ray Rietveld technique for x=1, 2, and 3. The lattice parameters a, b, c, and V were found to decrease linearly as the Sr at site 4h was replaced by Ca. The structure features chains of edge-sharing PbO6 octahedra, linked by seven-coordinated (Ca/Sr)–O monocapped trigonal prisms. The structure is similar to that of Pb3O4, which can be reformulated as Pb2IIPbIVO4. X-ray diffraction patterns for the solid solution members SrCa3Pb2O8, Sr2Ca2Pb2O8, and Sr3CaPb2O8 were prepared for inclusion in the Powder Diffraction File.

Download Full-text

X-ray diffraction study and powder patterns of double-perovskites Sr2RSbO6 (R = Pr, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er, Tm, Yb, and Lu)

Powder Diffraction ◽

10.1017/s0885715614000566 ◽

2014 ◽

Vol 29 (4) ◽

pp. 371-378 ◽

Cited By ~ 5

Author(s):

W. Wong-Ng ◽

J. A. Kaduk ◽

M. Luong ◽

Q. Huang

Keyword(s):

Diffraction Study ◽

Crystal Structures ◽

Powder Diffraction ◽

Double Perovskite ◽

Lattice Parameters ◽

Double Perovskites ◽

X Ray Diffraction ◽

Powder Diffraction File ◽

X Ray ◽

Diffraction Patterns

The X-ray diffraction powder patterns were prepared and the crystal structures were refined for the double-perovskite series of compounds, Sr2RSbO6 (R = Pr, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er, Tm, Yb, and Lu). We found the structures of the entire Sr2RSbO6 series to be monoclinic with space group P21/n (no. 14), and Z = 2. From R = Lu to Pr, the lattice parameters “a” range from 5.7779(2) to 5.879 05(8) Å, “b” range from 5.7888(2) to 5.969 52(9) Å, “c” range from 8.1767(3) to 8.369 20(12) Å, “β” range from 90.112(2)° to 90.313(1)°, and “V” range from 273.483(4) to 293.714(7) Å3. These lattice parameters follow the well-established trend of “lanthanide contraction”. The R3+ and Sb5+ ions are found to be fully ordered in the double-perovskite arrangement of alternating corner-sharing octahedra in a zigzag fashion. The SrO12, RO6, and SbO6 cages are all found to have distorted coordination environments. Powder diffraction patterns of these compounds have been prepared, submitted, and published in the Powder Diffraction File.

Download Full-text

Evaluation of Reference X-ray Diffraction Patterns in the ICDD Powder Diffraction File

Advances in X-ray Analysis ◽

10.1154/s0376030800014683 ◽

1990 ◽

Vol 34 ◽

pp. 369-376

Author(s):

G. J. McCarthy ◽

J. M. Holzer ◽

W. M. Syvinski ◽

K. J. Martin ◽

R. G. Garvey

Keyword(s):

Powder Diffraction ◽

X Ray Diffraction ◽

Powder Diffraction File ◽

Cd Rom ◽

X Ray ◽

Binary Oxides ◽

Diffraction Patterns ◽

Input Format ◽

Good Agreement

AbstractProcedures and tools for evaluation of reference x-ray powder patterns in the JCPDSICDD Powder Diffraction File are illustrated by a review of air-stable binary oxides. The reference patterns are evaluated using an available microcomputer version of the NBS*A1DS83 editorial program and PDF patterns retrieved directly from the CD-ROM in the program's input format. The patterns are compared to calculated and experimental diffractograms. The majority of the oxide patterns have been found to be in good agreement with the calculated and observed diffractograms, but are often missing some weak reflections routinely observed with a modern diffractometer. These weak reflections are added to the PDF pattern. For the remainder of the phases, patterns are redetermined.

Download Full-text

The X-Ray Powder Diffraction Patterns and Crystal Structure for Al2M3Y(M=Cu, Ni)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.950.48 ◽

2014 ◽

Vol 950 ◽

pp. 48-52

Author(s):

De Gui Li ◽

Ming Qin ◽

Liu Qing Liang ◽

Zhao Lu ◽

Shu Hui Liu ◽

...

Keyword(s):

Crystal Structure ◽

Powder Diffraction ◽

Diffraction Data ◽

Hexagonal Structure ◽

Argon Atmosphere ◽

X Ray Diffraction ◽

High Quality ◽

X Ray ◽

Arc Melting ◽

Diffraction Patterns

The Al2M3Y(M=Cu, Ni) compound was synthesized by arc melting under argon atmosphere. The high-quality powder X-ray diffraction data of Al2M3Y have been presented. The refinement of the X-ray diffraction patterns for the Al2M3Y compound show that the Al2M3Y has hexagonal structure, space groupP6/mmm(No.191), with a = b = 5.1618(2) Å, c = 4.1434(1) Å,V= 95.6 Å3,Z= 1,ڑx= 5.7922 g/cm3,F30= 155.5(0.0057, 34), RIR = 2.31 for Al2Cu3Y, and with a = b = 5.0399(1) Å, c = 4.0726(1) Å,V= 89.59 Å3,Z= 1,ڑx= 5.9118 g/cm3,F30= 135.7(0.0072, 30), RIR = 2.54 for Al2Ni3Y.

Download Full-text

X-ray powder diffraction analysis of the heteropoly-molybdate (MoO2)0.5PMo14O42

Powder Diffraction ◽

10.1154/1.1575762 ◽

2003 ◽

Vol 18 (3) ◽

pp. 236-239 ◽

Cited By ~ 4

Author(s):

L. Marosi ◽

J. Cifré ◽

C. Otero Areán

Keyword(s):

Catalytic Activity ◽

Diffraction Analysis ◽

Computer Modeling ◽

Powder Diffraction ◽

Rietveld Analysis ◽

Nitrogen Atmosphere ◽

Unit Cell ◽

X Ray Diffraction ◽

X Ray ◽

Diffraction Patterns

The new heteropoly blue compound (MoO2)0.5PMo14O42, which is relevant in the context of catalytic activity of heteropoly-molybdates, was prepared by controlled thermolysis of (NH4)3PMo12O40 at 730 K in a nitrogen atmosphere. Powder X-ray diffraction analysis showed that this compound has a cubic unit cell, space group Pn3m (No. 224), with ao=11.795(2) Å, Z=2 and DXR=4.2466 g cm−3. Computer modeling and Rietveld analysis of powder diffraction patterns led to a proposed structure of the corresponding Keggin-cage unit PMo14O42.

Download Full-text

Powder X-Ray Data for Synthetic Anhydrous Sodium Zirconium Silicates

Powder Diffraction ◽

10.1017/s0885715600012653 ◽

1987 ◽

Vol 2 (3) ◽

pp. 176-179 ◽

Cited By ~ 1

Author(s):

G. Wilson ◽

F. P. Glasser

Keyword(s):

Solid State ◽

Diffraction Pattern ◽

Powder Diffraction ◽

Solid State Reaction ◽

The Other ◽

X Ray Diffraction ◽

Powder Diffraction File ◽

X Ray ◽

Sodium Zirconium ◽

Diffraction Patterns

AbstractA systematic survey of phase formation in the Na2O-ZrO2-SiO2 system has revealed inconsistencies in the number and identity of ternary phases, and of their X-ray powder data. The phases Na2ZrSiO5, Na4Zr2Si3O12, Na2ZrSi2O7 and Na2ZrSi4O11 were prepared by solid-state reaction and their experimental X-ray diffraction patterns measured. Calculated X-ray diffraction patterns were generated by computer, using published crystallographic data, and critically compared with the experimentally observed values. The unit-cell constants were redefined to a greater accuracy than the presently accepted values published in the Powder Diffraction File. Only Na4Zr2Si3O12 produced an X-ray diffraction pattern which agreed with that previously published; those from the other phases were significantly different in both the intensities and positions of the reflections. Data for synthetic Na2ZrSi4O11 identical to the mineral vlasovite are reported.

Download Full-text

Powder X-ray diffraction and Rietveld analysis of La1−xBaxCoO3 (0

Powder Diffraction ◽

10.1154/1.2358363 ◽

2006 ◽

Vol 21 (4) ◽

pp. 304-306 ◽

Cited By ~ 13

Author(s):

Wanju Luo ◽

Fangwei Wang

Keyword(s):

Phase Transformation ◽

Bond Length ◽

Structural Properties ◽

Powder Diffraction ◽

Bond Angle ◽

Structural Phase ◽

Rietveld Analysis ◽

X Ray Diffraction ◽

Structural Phase Transformation ◽

X Ray

Detailed structural properties of La1−xBaxCoO3 (LBCO) have been investigated by means of X-ray powder diffraction and Rietveld analysis. A structural phase transformation from R3c to Pm3m at x=0.30–0.35 has been detected based on a comparison between the refinements of R3c and Pm3m. The Co–O bond length of the CoO6 octahedron expanded rapidly with increasing Ba content when x<0.1, and then it leveled off and kept constant at 0.1⩽x⩾0.35, where the Co–O–Co bond angle reaches 180°. The Co–O bond length expansion resumed with increasing Ba content beyond x=0.35.

Download Full-text

A Rietveld-analysis program for X-ray powder spectro-diffractometry

Powder Diffraction ◽

10.1017/s088571560001037x ◽

1999 ◽

Vol 14 (2) ◽

pp. 106-110 ◽

Cited By ~ 3

Author(s):

Yanan Xiao ◽

Shinjiro Hayakawa ◽

Yohichi Gohshi ◽

Masaharu Oshima ◽

Fujio Izumi ◽

...

Keyword(s):

Crystal Structure ◽

Powder Diffraction ◽

Absorption Edge ◽

Rietveld Method ◽

Rietveld Analysis ◽

Anomalous Scattering ◽

Analysis Program ◽

X Ray ◽

Diffraction Patterns ◽

X Ray Absorption

In order to exploit X-ray powder spectro-diffractometry, the program RIETAN-97ß for refining crystal structure and lattice parameters by the Rietveld method was modified extensively. The resulting software can be used to refine anomalous scattering factors, fr and fi, for specified crystallographic sites near the X-ray absorption edge of a particular element. The effectiveness of the modified software was tested by using powder diffraction patterns simulated by the original RIETAN-97ß software and a series of measured powder diffraction patterns of Fe3O4 with incident X-ray energies near the absorption edge of iron.

Download Full-text

X-ray powder diffraction studies of (BaxSr1−x)2Co2Fe12O22 and (BaxSr1−x)Co2Fe16O27

Powder Diffraction ◽

10.1017/s0885715614001432 ◽

2015 ◽

Vol 30 (2) ◽

pp. 139-148 ◽

Cited By ~ 2

Author(s):

W. Wong-Ng ◽

G. Liu ◽

Y. Yan ◽

K. R. Talley ◽

J. A. Kaduk

Keyword(s):

Seebeck Coefficient ◽

Powder Diffraction ◽

Lattice Parameters ◽

Hexagonal Ferrite ◽

Layered Compounds ◽

X Ray Diffraction ◽

Powder Diffraction File ◽

Space Group ◽

X Ray ◽

Diffraction Patterns

X-ray structural characterization and X-ray reference powder patterns have been determined for two series of iron- and cobalt-containing layered compounds (BaxSr1−x)2Co2Fe12O22 (x = 0.2, 0.4, 0.6, 0.8) and (BaxSr1−x)Co2Fe16O27 (x = 0.2, 0.4, 0.6, 0.8). The (BaxSr1−x)2Co2Fe12O22 series of compounds crystallized in the space group R$\bar 3$m (No. 166), with Z = 3. The structure is essentially that of the Y-type hexagonal ferrite, BaM2+Fe63+O11. The lattice parameters range from a = 5.859 15(8) to 5.843 72(8) Å, and c = 43.4975(9) to 43.3516(9) Å for x = 0.2 to 0.8, respectively. The (BaxSr1−x)Co2Fe16O27 series (W-type hexagonal ferrite) crystallized in the space group P63/mmc (No. 194) and Z = 2. The lattice parameters range from a = 5.902 05(12) to 5.8979(2) Å and c = 32.9002(10) to 32.8110(13) Å for x = 0.2 to 0.8. Results of measurements of the Seebeck coefficient and resistivity of these two sets of samples indicated that they are insulators. Powder X-ray diffraction patterns of these two series of compounds have been submitted to be included in the Powder Diffraction File.

Download Full-text