Powder X-Ray Diffraction Data on Polymorphism of RbBSi2O6 and Crystal Structure of Its High-Temperature Modification

2018 ◽  
Vol 59 (8) ◽  
pp. 1995-2000
Author(s):  
M. G. Krzhizhanovskaya ◽  
R. S. Bubnova ◽  
S. K. Filatov
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Modification ◽  
High Temperature Modification

Crystal structure and powder diffraction pattern of high-temperature modification of Pd73Sn14Te13

2007 ◽  
Vol 22 (4) ◽  
pp. 334-339 ◽  
Author(s):  
F. Laufek ◽  
A. Vymazalová ◽  
J. Plášil
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Title Compound ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Temperature Modification ◽  
High Temperature Modification

Crystal structure of high-temperature modification of Pd73Sn14Te13 has been refined by the Rietveld method from laboratory X-ray powder diffraction data. Refined crystallographic data of Pd73Sn14Te13 are a=7.6456(3) Å, c=13.9575(9) Å, V=706.75(6) Å3, space group P63cm (No. 185), Z=6, and Dx=10.71 g/cm3. The title compound is isostructural with Pd5Sb2 and Ni5As2; it can be considered as a stacking and filling variant of the Ni2In structure. An important structural feature in the high-temperature modification of Pd73Sn14Te13 is the presence of various Pd-Pd bonds.

scholarly journals High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Mixed Cation ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

Zur Kenntnis des Argyrodit-Strukturtyps: Die Kristallstruktur von Ag8SiS6 / The Argyrodite Structure Type : The Crystal Structure of Ag8SiS6

1977 ◽  
Vol 32 (4) ◽  
pp. 373-379 ◽  
Author(s):  
Bernt Krebs ◽  
Jürgen Mandt
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Room Temperature ◽  
Structure Type ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Temperature Modification ◽  
Face Centered ◽  
Temperature Factors ◽  
High Temperature Modification

The room temperature modification of Ag8SiS6 is orthorhombic, space group Pna21, with α = 15.024, b = 7.428, c = 10.533 Å, Z = 4. A complete single crystal X-ray structure analysis shows the structure to contain tetrahedral SiS4(4-) units (Si-S 2.094(12) ... 2.130(12) Å) besides isolated sulfide groups coordinated by Ag; the compound may thus be formulated as Ag8(SiS4)(S)2. The coordination of the Ag atoms by sulfur is distorted tetrahedral (Ag-S 2.557...2.757 A), approximately trigonal planar (Ag-S 2.386...2.775 A, with one additional weakly bonded axial S at 2.991 ... 3.330 Å), or linear (Ag-S 2.414... 2.443 Å). Within the (ordered) Ag sublattice the temperature factors are significantly higher than for Si and S, indicating a certain mobility of the Ag atoms. The arrangement of the thiosilicate -sulfide part of the structure is pseudocubic face-centered, showing the close structural relationship to the disordered cubic high temperature modification of Ag8GeTe6.

Synthesis and structural characterization of Li3Y(BO3)2

2017 ◽  
Vol 72 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Sebastian Bräuchle ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Boric Acid ◽  
Structural Characterization ◽  
Diffraction Data ◽  
Lithium Carbonate ◽  
X Ray Diffraction ◽  
X Ray

AbstractLi3Y(BO3)2 was prepared by high-temperature solid state synthesis at 900°C in a platinum crucible from lithium carbonate, boric acid, and yttrium(III) oxide. The compound crystallizes monoclinically in the space group P21/c (no. 14) (Z=4) isotypically to Li3Gd(BO3)2. The structure was refined from single-crystal X-ray diffraction data: a=8.616(3), b=6.416(3), c=10.014(2) Å, β=116.6(2)°, V=494.9(3) Å3, R1=0.0211, and wR2=0.0378 for all data. The crystal structure of Li3Y(BO3)2 consists of [Y2O14] dinuclear units, which are interconnected to each other by planar B(1)O3 groups and LiO4 tetrahedra via common edges and corners along the a axis.

scholarly journals Synthesis and Crystal Structure of the Praseodymium Orthoborate λ -PrBO3

2010 ◽  
Vol 65 (10) ◽  
pp. 1206-1212 ◽  
Author(s):  
Almut Haberer ◽  
Reinhard Kaindl ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
Title Compound ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
High Pressure High Temperature

The praseodymium orthoborate λ -PrBO3 was synthesized from Pr6O11, B2O3, and PrF3 under high-pressure / high-temperature conditions of 3 GPa and 800 °C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature. The title compound crystallizes in the orthorhombic aragonite-type structure, space group Pnma, with the lattice parameters a = 577.1(2), b = 506.7(2), c = 813.3(2) pm, and V = 0.2378(2) nm3, with R1 = 0.0400 and wR2 = 0.0495 (all data). Within the trigonal-planar BO3 groups, the average B-O distance is 137.2 pm. The praseodymium atoms are ninefold coordinated by oxygen atoms.

Crystal structure and X-ray diffraction data of a new hexagonal perovskite compound, Ba4CuNb3O12

2011 ◽  
Vol 26 (3) ◽  
pp. 244-247
Author(s):  
N. Kumada ◽  
W. Zhang ◽  
Q. Dong ◽  
T. Mochizuki ◽  
Y. Yonesaki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Chemical Composition ◽  
Solid State ◽  
Diffraction Data ◽  
Solid State Reaction ◽  
Inert Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Copper

A new barium copper niobate, Ba4CuNb3O12, was successfully prepared by high-temperature solid-state reaction in an inert atmosphere. Rietveld-refinement analysis of the XRD data of the compound showed that it has the 8H-type hexagonal perovskite structure with space group P63/mmc (#194), a = 5.830(1) Å, c = 19.123(1) Å, and chemical composition of Ba4Cu1.84Nb2.16O12-δ.

Synthesis and structural characterization of Li3K3Eu7(BO3)9

2017 ◽  
Vol 72 (12) ◽  
pp. 959-965 ◽  
Author(s):  
Sebastian Bräuchle ◽  
Markus Seibald ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Potassium Carbonate ◽  
Diffraction Data ◽  
Lithium Carbonate ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray

AbstractLi3K3Eu7(BO3)9 was prepared by high-temperature solid state synthesis at 900°C in a platinum crucible from lithium carbonate, potassium carbonate, boric acid, and europium(III) oxide. The title compound crystallizes in the orthorhombic space group Pca21 (no. 29) (Z=4). The structure was refined from single-crystal X-ray diffraction data: a=21.126(2), b=6.502(2), c=17.619(2) Å, V=2420.1(2) Å3, R1=0.0183 and wR2=0.0412 for all data. The crystal structure of Li3K3Eu7(BO3)9 is isotypic to Li3K3Y7(BO3)9 featuring isolated BO3 units and LiO6 octahedra forming [Li3B4O21] units in the ac plane, which are linked by additional BO3 units. The K+ and Eu3+ cations are arranged in the cavities of the structure.

Incommensurately modulated crystal structure of flamite – natural analogue of \alpha _{\rm H}^{\prime}-Ca2SiO4

2019 ◽  
Vol 75 (6) ◽  
pp. 1137-1143
Author(s):  
Sergey V. Rashchenko ◽  
Yurii V. Seryotkin ◽  
Ella V. Sokol ◽  
Svetlana N. Kokh
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Ambient Temperature ◽  
Single Crystal ◽  
Diffraction Data ◽  
Natural Analogue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Incommensurate Modulation ◽  
Cation Sites

Crystal structures of unquenchable high-temperature polymorphs of Ca2SiO4, important in cement chemistry, have eluded single-crystal X-ray analysis. However, the problem may be addressed by studying chemically stabilized Ca2SiO4 polymorphs at ambient temperature. Here an incommensurately modulated crystal structure of flamite [Pnma(0β0)00s, q = 0.2728 (2)b*, a = 6.8588 (2) Å, b = 5.4301 (2) Å, c = 9.4052 (3) Å] is described. It is a mineral analogue of orthorhombic \alpha _{\rm H}^{\prime}-Ca2SiO4 (stable between 1160 and 1425°C), naturally stabilized by substitution with phosphorus. The incommensurate modulation results from wave-like displacement of cation sites accompanied by tilting of (Si,P)O4 tetrahedra and variation of the Na/(Ca + Na + K) ratio along the modulation period. The studied sample from Hatrurim Basin (Negev Desert, Israel) with composition (Ca1.75K0.12Na0.12)1.99(Si0.74P0.26)1.00O4 also demonstrates pseudomerohedral cyclic twinning around the a axis, which results from pseudohexagonal topology of the crystal structure and complicates the indexing of X-ray diffraction data.

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