Crystallographic studies of BaR2ZnO5 (R=La, Nd, Dy, Ho, Er, and Y)

1998 ◽  
Vol 13 (3) ◽  
pp. 144-151 ◽  
Author(s):  
Winnie Wong-Ng ◽  
Brian Toby ◽  
William Greenwood
Keyword(s):  
Neutron Diffraction ◽  
Crystal Structures ◽  
Lattice Parameters ◽  
Trigonal Prism ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

The crystal structures of BaR2ZnO5, where R=La, Nd, Dy, Ho, and Y, were studied by neutron diffraction, and that of the Er analog was investigated by synchrotron X-ray diffraction. Two structure types were confirmed for this series of compounds and agreed with those reported in literature. The compounds with a smaller size of R (R=Dy, Ho, Y, and Er) are isostructural to the orthorhombic “green phase (BaY2CuO5)” compounds. The cell parameters for compounds with the R=Er to Dy range from a=7.0472(1) Å to 7.0944(1) Å, b=12.3022(1) Å to 12.3885(2) Å, and c=5.6958(1) Å to 5.7314(1) Å, respectively. R is 7-fold coordinated inside a monocapped trigonal prism. These prisms share edges to form wavelike chains parallel to the long b-axis. The Ba atoms reside in 11-fold coordinated cages. The compounds which contain a larger size R (R=La and Nd) crystallize in the tetragonal I4/mcm space group, but are not isostructural to the “brown phases” BaR2CuO5. The lattice parameters for the La and Nd analogs are a=6.9118(1) Å, c=11.6002(2) Å for BaLa2ZnO5, and a=6.7608(1) Å and c=11.5442(2) Å for BaLa2ZnO5. The structure consists of ZnO4 tetrahedral groups (instead of planar CuO4 groups as found in the brown phase) with Ba ions inserted in between. The structure can be viewed as consisting of alternate layers of Zn-Ba-O and Nd-O extending infinitely in the xy plane and perpendicular to the z-axis.

Synthesis and Crystal Structures of ATi[Nb6Cl18] Compounds (A = K, Rb, Cs, In, Tl)

2000 ◽  
Vol 55 (2) ◽  
pp. 139-144 ◽  
Author(s):  
A. Nägele ◽  
E. Anokhina ◽  
J. Sitar ◽  
H.-J. Meyer ◽  
A. Lachgar
Keyword(s):  
Structure Refinement ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Coordination Environment ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Crystal System ◽  
Rhombohedral Crystal

Abstract New quaternary niobium cluster chlorides corresponding to the general formula ATi[Nb6Cl18] (A = K, Rb, Cs, In, Tl) have been synthesized in sealed quartz tubes at 720 °C, starting from stoichiometric amounts of NbCl5, niobium metal, TiCl3, and ACl (A = K, Rb, Cs), or In or Tl metals. The structures of RbTi[Nb6Cl18] and CsTi[Nb6Cl18] were determined using single­ crystal X-ray diffraction. RbTi[Nb6Cl18] crystallizes in the rhombohedral crystal system, space group R3̄ (no. 148), Z = 3, with lattice parameters: a = 9.163(4), c = 25.014(14) Å (hexagonal setting). The structure refinement converged to R1 = 0.044 and wR2 = 0.058 for all data. In this structure, discrete [Nb6Cl18]4-cluster units are linked by Rb+ and Ti3+ cations, located in a 12-coordinated anticubeoctahedral and octahedral chloride coordination environment, respectively. In contrast, CsTi[Nb6Cl18] crystallizes in the trigonal crystal system, space group P3̄1c (no. 163), Z = 2. The lattice parameters were determined to be a = 9.1075(6), c = 17.0017(8) Å. The structure refinement gives the reliability factors R1 = 0.029 and wR2 = 0.063 for all data. The structure is built up of discrete octahedral [Nb6Cl18]4- cluster units, linked by Cs+ and Ti3+ cations which are located in a distorted hexagonal antiprismatic and octahedral chloride coordination environment, respectively. The structures of the compounds ATi[Nb6Cl18] (A = K, In, Tl) were found to be isotypic with RbTi[Nb6Cl18], and their unit cell parameters were refined using X-ray powder diffraction analysis.

Kristallstrukturen und Schwingungsspektren zweier isomerer Oktadekawolframatodiarsenate, (NH4)6As2W18O62 ·nH2O/ Crystal Structures and Vibrational Spectra of Two Isomers of Octadecatungsto-diarsenate (NH4)6As2W18O62 · nH2O

1987 ◽  
Vol 42 (8) ◽  
pp. 951-958 ◽  
Author(s):  
Holger Neubert ◽  
Joachim Fuchs
Keyword(s):  
Crystal Structures ◽  
Vibrational Spectra ◽  
Lattice Parameters ◽  
Fold Axis ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Polar Groups ◽  
Dawson Structure

AbstractSix possible structures of As2W18O626- are discussed, and an exact nomenclature is proposed. The structures of the isomeric title compounds (I and II) were determined by X-ray diffraction. I crystallizes in space group P I with lattice parameters a = 12.965(4), b = 14.803(5), c = 18.515(6) Å; a = 96.280(23)°, β = 91.420(25)°, γ = 115.320(25)°. The anion has the configuration first observed in K6P2W18O62 · 14H2O (Dawson-structure). II was not known until now. It crystallizes in the trigonal space group R3 with lattice parameters a - b - 37.857(32). c = 13.108( 13) Å; α = β = 90°, γ = 120°. The structure of this anion differs from the Dawson-structure by the 60° rotation of both polar groups of three WO6-octahedra (β-type), followed by the 60° rotation of one of the two new AsW9O31-units. Both rotations are about the 3-fold axis. The anion is centrosymm etric. Vibrational spectra and preparation of the isomers are described.

Powder X-ray diffraction study of LaCo0.5Ni0.5O3−δ and LaCo0.5Fe0.5O3−δ

2003 ◽  
Vol 18 (2) ◽  
pp. 159-161 ◽  
Author(s):  
N. P. Vyshatko ◽  
V. V. Kharton ◽  
A. L. Shaula ◽  
F. M. B. Marques
Keyword(s):  
Diffraction Study ◽  
Crystal Structures ◽  
Solid Solutions ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

The crystal structures of LaCo0.5Ni0.5O3−δ and LaCo0.5Fe0.5O3−δ solid solutions, studied by powder X-ray diffraction, were found to be rhombohedral perovskite. The unit cell parameters in the hexagonal setting are a=5.491(6) Å and c=13.231(3) Å for LaCo0.5Fe0.5O3−δ, and a=5.464(4) Å and c=13.125(3) Å for LaCo0.5Ni0.5O3−δ. The space group is R3c (No. 167).

scholarly journals Crystal structures and comparisons of huntite aluminum borates REAl3(BO3)4 (RE = Tb, Dy and Ho)

2020 ◽  
Vol 76 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Saehwa Chong ◽  
Brian J. Riley ◽  
Zayne J. Nelson ◽  
Samuel N. Perry
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Structural Parameters ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Slow Cooling ◽  
Spontaneous Crystallization ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Three huntite-type aluminoborates of stoichiometry REAl3(BO3)4 (RE = Tb, Dy and Ho), namely, terbium/dysprosium/holmium trialuminium tetrakis(borate), were synthesized by slow cooling within a K2Mo3O10 flux with spontaneous crystallization. The crystal structures were determined using single-crystal X-ray diffraction (SC-XRD) data. The synthesized borates are isostructural to the huntite [CaMg3(CO3)4] structure and crystallized within the trigonal R32 space group. The structural parameters were compared to literature data of other huntite REAl3(BO3)4 crystals within the R32 space group. All three borates fit well into the trends calculated from the literature data. The unit-cell parameters and volumes increase linearly with larger RE cations whereas the densities decrease. All of the crystals studied were refined as inversion twins.

New Calcium Hydride Halides with Familiar Structures. Syntheses and Crystal Structures of Ca7H12Cl2 and Ca2H3Br

2010 ◽  
Vol 65 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Structures ◽  
Lattice Parameters ◽  
Calcium Hydride ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Compounds

Single crystals of Ca7H12Cl2 and Ca2H3Br were obtained by reacting stoichiometric amounts of CaH2 and CaX2 (X = Cl, Br) at 1300 K in the presence of surplus Ca metal for 13 h in silicajacketed Nb ampoules. The crystal structures of the new compounds were determined by means of single-crystal X-ray diffraction. Ca7H12Cl2 crystallizes isotypical to Ba7Cl2F12 and Sr7H12Cl2 in the hexagonal space group P¯6 (no. 174) with the lattice parameters a = 936.51(8), c = 368.65(2) pm, while Ca2H3Br crystallizes in a stuffed anti-CdI2 structure isotypical to Ba2H3Cl and therefore adopts the space group P¯3m1 (no. 164) with the lattice parameters a = 391.37(6) and c = 697.04(13) pm. The structural results are corroborated by EUTAX calculations on the title compounds and the comparison of these results to those for CaH2, CaX2 and CaHX (X = Cl, Br). Similar calculations on the hypothetical compound “Ca7H12Br2” give a possible explanation for the preferred formation of the compound Ca2H3Br.

Synthesis of cis- and trans-platinum compounds with pyrimidine and crystal structures of trans-[Pt(pyrimidine)2X2] where X = Cl and Br

1981 ◽  
Vol 59 (2) ◽  
pp. 195-198 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
R. Melanson
Keyword(s):  
Crystal Structures ◽  
Platinum Atom ◽  
Platinum Compounds ◽  
X Ray Diffraction ◽  
Trans Isomers ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Cis And Trans

cis- and trans-[Pt(pm)2X2] where pm = pyrimidine and X = Cl, Br, have been synthesized. The cis-compounds were isolated from the reaction of K2PtCl4 and pm in water, while the trans-isomers were obtained by isomerization of cis-[Pt(pm2X2] in DMF in the presence of pm.The crystal structures of the two compounds trans-[Pt(pm)2X2] have been determined by X-ray diffraction. The two compounds (X = Br and Cl) are isostructural. The crystals belong to the monoclinic P21/c space group. The cell parameters are a = 4.787(3), b = 14.257(7), c = 8.503(3) Å and β = 99.33(4)° when X = Cl and a = 4.826(3), b = 14.822(5), c = 8.516(5) Å and β = 101.26(4)° when X = Br. The platinum atom is located on a centre of symmetry at the origin and Z = 2. The residual factors are R = 0.029 and Rw = 0.036 (X = Cl) and R = 0.036 and Rw = 0.035 (X = Br).

scholarly journals Crystal-to-Crystal Transformation from K2[Co(C2O4)2(H2O)2]·4H2O to K2[Co(μ-C2O4)(C2O4)]

2021 ◽  
Vol 7 (6) ◽  
pp. 77
Author(s):  
Bin Zhang ◽  
Yan Zhang ◽  
Guangcai Chang ◽  
Zheming Wang ◽  
Daoben Zhu
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Crystal Structures ◽  
Molecular Crystal ◽  
Trigonal Prism ◽  
Space Group ◽  
Cell Parameters ◽  
Oxalate Anion ◽  
Crystal Transformation ◽  
Antiferromagnetic Ordering

Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) is obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O with a yield of 60%. It is crystallized in the triclinic with space group P1 and cell parameters: a = 7.684(1) Å, b = 9.011(1) Å, c = 10.874(1) Å, α = 72.151(2)°, β = 70.278(2)°, γ = 80.430(2)°, V = 670.0(1) Å3, Z = 2 at 100 K. 1 is composed of K+, mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. Co2+ is coordinated by two bidentated oxalate anion and two H2O in an octahedron environment. There is a hydrogen bond between mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. K2[Co(μ-C2O4)(C2O4)] (2) is obtained from 1 by dehydration. The cell parameters of 2 are a = 8.460(5) Å, b = 6.906 (4) Å, c = 14.657(8) Å, β = 93.11(1)°, V = 855.0(8) Å3 at 100 K, with space group in P2/c. It is composed of K+ and zigzag [Co(μ-C2O4)(C2O42−]n chain. Co2+ is coordinated by two bisbendentate oxalate and one bidentated oxalate anion in trigonal-prism. 1 is an antiferromagnetic molecular crystal. The antiferromagnetic ordering at 8.2 K is observed in 2.

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Binary Compound ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

scholarly journals β-Y(BO2)3 – a new member of the β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu) structure family

2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).

Superstructure formation in the solid solution Sc3Pt3−xIn3 (x = 0–0.93)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nataliya L. Gulay ◽  
Rolf-Dieter Hoffmann ◽  
Jutta Kösters ◽  
Yaroslav M. Kalychak ◽  
Stefan Seidel ◽  
...  
Keyword(s):  
Solid Solution ◽  
Diffraction Data ◽  
High Frequency ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Platinum Content ◽  
Arc Melting ◽  
Modulation Vector

Abstract The equiatomic indide ScPtIn (ZrNiAl type, space group P 6 ‾ $‾{6}$ 2m) shows an extended solid solution Sc3Pt3–xIn3. Several samples of the Sc3Pt3–xIn3 series were synthesized from the elements by arc-melting and subsequent annealing, or directly in a high frequency furnace. The lowest platinum content was observed for Sc3Pt2.072(3)In3. All samples were characterized by powder X-ray diffraction and their lattice parameters and several single crystals were studied on the basis of precise single crystal X-ray diffractometer data. The correct platinum occupancy parameters were refined from the diffraction data. Decreasing platinum content leads to decreasing a and c lattice parameters. Satellite reflections were observed for the Sc3Pt3–xIn3 crystals with x = 0.31–0.83. These satellite reflections could be described with a modulation vector ( 1 3 , 1 3 , γ ) $\left(\frac{1}{3},\frac{1}{3},\gamma \right)$ ( γ = 1 2 $\gamma =\frac{1}{2}$ c* for all crystals) and are compatible with trigonal symmetry. The interplay of platinum filled vs. empty In6 trigonal prisms is discussed for an approximant structure with space group P3m1.

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