Crystal Structures and Phase-Transitions Analysis of the Double Perovskites Sr2Co1−xNixTeO6 (x = 0.25, 0.5 and 0.75) Using X-ray Powder Diffraction, Raman and Infrared Spectroscopy

2019 ◽  
Vol 48 (8) ◽  
pp. 4866-4876 ◽  
Author(s):  
A. Zaraq ◽  
B. Orayech ◽  
J. M. Igartua ◽  
A. El Bouari
2014 ◽  
Vol 29 (4) ◽  
pp. 371-378 ◽  
Author(s):  
W. Wong-Ng ◽  
J. A. Kaduk ◽  
M. Luong ◽  
Q. Huang

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.


2003 ◽  
Vol 18 (2) ◽  
pp. 128-134 ◽  
Author(s):  
A. Le Bail ◽  
A.-M. Mercier

The crystal structures of the chiolite-related room temperature phases α-Na5M3F14 (MIII=Cr,Fe,Ga) are determined. For all of them, the space group is P21/n, Z=2; a=10.5096(3) Å, b=7.2253(2) Å, c=7.2713(2) Å, β=90.6753(7)° (M=Cr); a=10.4342(7) Å, b=7.3418(6) Å, c=7.4023(6) Å, β=90.799(5)° (M=Fe), and a=10.4052(1) Å, b=7.2251(1) Å, c=7.2689(1), β=90.6640(4)° (M=Ga). Rietveld refinements produce final RF factors 0.036, 0.033, and 0.035, and RWP factors, 0.125, 0.116, and 0.096, for MIII=Cr, Fe, and Ga, respectively. The MF6 polyhedra in the defective isolated perovskite-like layers deviate very few from perfect octahedra. Subtle octahedra tiltings lead to the symmetry decrease from the P4/mnc space group adopted by the Na5Al3F14 chiolite aristotype to the P21/n space group adopted by the title series. Facile twinning precluded till now the precise characterization of these compounds.


Author(s):  
Robert E. Dinnebier ◽  
Hanne Nuss ◽  
Martin Jansen

AbstractThe crystal structures of solvent-free lithium, sodium, rubidium, and cesium squarates have been determined from high resolution synchrotron and X-ray laboratory powder patterns. Crystallographic data at room temperature of Li


2006 ◽  
Vol 45 (8) ◽  
pp. 1313-1317 ◽  
Author(s):  
Martin U. Schmidt ◽  
Detlef W. M. Hofmann ◽  
Christian Buchsbaum ◽  
Hans Joachim Metz

2012 ◽  
Vol 194 ◽  
pp. 5-9 ◽  
Author(s):  
Yuriy Verbovytskyy ◽  
Antonio Pereira Gonçalves

Seven new ternary RZn1+xGa3-x (R = Ce, Pr, Nd, Sm, Ho and Er) and R5Zn2Ga17 (R = Ce) phases are synthesized for the first time. Their crystal structures are solved on basis of X-ray powder diffraction data. The above mentioned compounds belong to the BaAl4 (space group I4/mmm) and Rb5Hg19 (space group I4/m) structure types. Details of the structure of the Ce5Zn2Ga17 compound and relationship with RZn2-xGa2+x (BaAl4 type) and R3Zn8-xGa3+x (La3Al11 type) are briefly discussed.


1979 ◽  
Vol 32 (3) ◽  
pp. 691 ◽  
Author(s):  
DW Smith ◽  
T Yeoh

(NMe4)2CuBrnC14-n and (NEt4)nCuBrnCl44-n (n = 1, 2, 3) have been prepared and characterized by X-ray powder diffraction and far-infrared spectroscopy. The tetramethylammonium compounds are isomorphous with each other and with the corresponding compounds where n = 0, 4. The tetraethylammonium compounds constitute another isomorphous series. All the compounds apparently contain discrete CuBrnCI4-n2- anions, with flattened tetrahedral configurations.


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