Chains of Condensed RuSm6/2 Octahedra in Sm3RuMg7 – A Ternary Ordered Version of the Ti6Sn5 Type

2011 ◽  
Vol 66 (6) ◽  
pp. 565-569 ◽  
Author(s):  
Stefan Linsinger ◽  
Rainer Pöttgen
Keyword(s):  
Intermetallic Compound ◽  
Single Crystal ◽  
Single Crystals ◽  
Polycrystalline Sample ◽  
Induction Melting ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
X Ray ◽  
Distorted Octahedral ◽  
Trigonal Prisms

The magnesium-rich intermetallic compound Sm3RuMg7 was synthesized by induction melting of the elements. Single crystals were grown by slow cooling of the polycrystalline sample. The structure was characterized by powder and single-crystal X-ray diffraction: ordered Ti6Sn5 type, P63/mmc, Z = 2, a = 1034.1(2), c = 611.3(1) pm, wR2 = 0.0216, 399 F2 values and 19 parameters. The ruthenium atoms have slightly distorted octahedral samarium coordination. These RuSm6/2 octahedra (Ru-Sm 279 pm) are condensed via common faces leading to chains in the c direction which are arranged in the form of a hexagonal rod packing. Between these rods the Mg2 atoms build chains of face-sharing trigonal prisms. Alternately these prisms are centered by Mg3 or capped by Mg1 atoms on the rectangular faces. Within the magnesium substructure the Mg-Mg distances range from 303 to 335 pm. The Mg3 site shows slight mixing with samarium, leading to the composition Sm3.16RuMg6.84 for the investigated crystal. The compounds RE3RuMg7 (RE = Gd, Tb) are isotypic.

New Quaternary Indides RE7Ni5–xGe3+xIn6 (RE = La, Nd, Sm)

2011 ◽  
Vol 66 (4) ◽  
pp. 433-436
Author(s):  
Nataliya Dominyuk ◽  
Vasyl I. Zaremba ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
X Ray ◽  
Arc Melting ◽  
Characteristic Features

The quaternary indides RE7Ni5−xGe3+xIn6 (RE = La,Nd, Sm) were synthesized from the elements by arc-melting. Single crystals were grown by slow cooling of the polycrystalline samples. The structures were characterized by powder and single-crystal X-ray diffraction: Ce7Ni4.73Ge3.27In6 type, P6/m, Z = 1, a = 1147.05(9), c = 426.82(4) pm, wR2 = 0.0652, 528 F2 values for La7Ni4.46Ge3.54In6, a = 1134.5(7), c = 407.1(7) pm, wR2 = 0.0419, 441 F2 values for Nd7Ni4.91Ge3.09In6, and a = 1133.5(2), c = 404.3(1) pm, wR2 = 0.0619, 498 F2 values for Sm7Ni4.31Ge3.69In6, with 25 parameters per refinement. Characteristic features of the RE7Ni5−xGe3+xIn6 structures are hexagonal, AlB2-related prisms around the RE1 atoms and a tricapped, trigonalprismatic coordination of the nickel atoms

ScPtP und LaPtP – Zwei Phosphide mit ,,inverser“ TiNiSi-Struktur / ScPtP and LaPtP – Two Phosphides with “Inverse” TiNiSi-Type Structure

2007 ◽  
Vol 62 (9) ◽  
pp. 1153-1156 ◽  
Author(s):  
Anette Imre ◽  
Albrecht Mewis
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Structures ◽  
Type Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molten Lead ◽  
Trigonal Prisms

Single crystals of ScPtP (orthorhombic, a = 6.437(1), b = 4.291(1), c = 7.550(2) Å ) were grown by reaction of the elements in molten lead (1000 °C), whereas LaPtP (orthorhombic, a = 7.268(1), b = 4.532(1), c = 7.864(2) Å ) was prepared by heating mixtures of the elements at 900 °C. Both phosphides were investigated by single crystal X-ray diffraction. Their crystal structures belong to the TiNiSi-type (Pnma; Z = 4), but the positions of the Ni and Si atoms are exchanged. Therefore the Pt atoms are located in the centers of trigonal prisms and the P atoms are coordinated by four Pt atoms in the shape of distorted tetrahedra.

scholarly journals Rerefinement of the crystal structure of trichloridosulfonium(IV) hexachloridouranate(V), (SCl3)[UCl6]

IUCrData ◽  
2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Holger Lars Deubner ◽  
Sergei I. Ivlev ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Lattice Parameters ◽  
Structure Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ionic Compound ◽  
Distorted Octahedral ◽  
Atomic Coordinates

Single crystals of trichloridosulfonium(IV) hexachloridouranate(V) were obtained from the reaction of uranium(IV) chloride with an excess of disulfur dichloride and studied by single-crystal X-ray diffraction. In comparison with the structure model reported previously [Sawodny et al. (1983). Z. Anorg. Allg. Chem. 499, 81–88.], the lattice parameters and fractional atomic coordinates were determined to a much higher precision, leading overall to an improved structure model. The ionic compound contains trigonal–pyramidal (SCl3)+ cations and slightly distorted octahedral [UCl6]− anions. The structure was refined as an inversion twin with a twin ratio of 4.4:1.

Superstructure formation in Sc5Cu2In4

2020 ◽  
Vol 235 (10) ◽  
pp. 417-422 ◽  
Author(s):  
Nataliya L. Gulay ◽  
Rolf-Dieter Hoffmann ◽  
Vasyl‘ I. Zaremba ◽  
Yaroslav M. Kalychak ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Symmetry Reduction ◽  
Type Structure ◽  
Induction Melting ◽  
Slow Cooling ◽  
Coinage Metal ◽  
X Ray ◽  
The Family

AbstractPolycrystalline Sc5Cu2In4 was synthesized by induction melting of the elements and small single crystals were obtained by a slow cooling sequence. Sc5Cu2In4 is the first coinage metal representative in the family of the so-called 5-2-4 intermetallics. The Zr5Ir2In4 type structure of Sc5Cu2In4 was refined from single crystal X-ray diffractometer data: Pnma, a = 1716.75(6), b = 677.94(12), c = 760.69(2) pm, wR2 = 0.0531, 1932 F2 values and 58 variables. Sc5Cu2In4 adopts a superstructure of the Lu5Ni2In4 type (doubling of the b axis and klassengleiche symmetry reduction from Pbam to Pnma), caused by dislocation of the copper atoms (puckering effect). Geometrically, Sc5Cu2In4 is a 4:1 intergrowth structure of distorted AlB2 and CsCl related slabs.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

scholarly journals Modeling of magneto-conductivity of bismuth selenide: a topological insulator

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Single Crystal ◽  
Single Crystals ◽  
X Ray Diffraction ◽  
Field Range ◽  
X Ray ◽  
Bulk Carriers ◽  
Different Temperatures

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).

scholarly journals Rubidium tetrafluoridobromate(III): redetermination of the crystal structure from single-crystal X-ray diffraction data

IUCrData ◽  
2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Artem V. Malin ◽  
Sergei I. Ivlev ◽  
Roman V. Ostvald ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar ◽  
Atomic Coordinates

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].

Crystallinity of YBa2Cu3O7−x single crystals grown by the pulling method

1996 ◽  
Vol 11 (4) ◽  
pp. 804-812 ◽  
Author(s):  
Y. Namikawa ◽  
M. Egami ◽  
S. Koyama ◽  
Y. Shiohara ◽  
H. Kutami
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Growth Direction ◽  
Annealed Sample ◽  
Seed Crystal ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Crystal Seed ◽  
Better Than

Large YBa2Cu3O7−x (Y123) single crystals (larger than 13 mm cubed) have been grown along the c-axis reproducibly by the modified pulling method. The crystallinity of Y123 single crystal was investigated by x-ray diffraction and x-ray topography. Crystals grown from an MgO single crystal seed had some low angle subgrain boundaries which tilted 0.1–0.8° from each other. These grain boundaries originated from the seed crystal, and the subgrains were extended along the growth direction from the seed crystal. Y123 single crystals with no marked subgrains in the whole area were obtained by using Y123 single subgrain crystal seeds. FWHM of the x-ray rocking curve for the crystal so produced was about 0.14°, which was much better than the spectrum consisting of several separated peaks obtained from the previous crystals. Tc onset of the annealed sample was about 93.6 K, and the transition width was about 0.9 K. The low angle subgrain boundaries did not seem to be effective pinning centers for the magnetic flux.

New Intermetallic Compounds RE4Co2Mg3 (RE = Pr, Gd, Tb, Dy) – Syntheses, Structure, and Chemical Bonding

2007 ◽  
Vol 62 (2) ◽  
pp. 162-168 ◽  
Author(s):  
Selcan Tuncel ◽  
Ute Ch. Rodewald ◽  
Samir F. Matar ◽  
Bernard Chevalier ◽  
Rainer Pöttgena
Keyword(s):  
Single Crystal ◽  
Intermetallic Compounds ◽  
Chemical Bonding ◽  
Structural Features ◽  
Induction Melting ◽  
Geometrical Constraint ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bonding Analysis ◽  
Magnesium Compounds

The magnesium compounds RE4Co2Mg3 (RE = Pr, Gd, Tb, Dy) were prepared by induction melting of the elements in sealed tantalum tubes. The samples were studied by powder X-ray diffraction. The structures of the gadolinium and of the terbium compound were refined from single crystal diffractometer data: Nd4Co2Mg3-type, P2/m, Z = 1, a = 754.0(4), b = 374.1(1), c = 822.5(3) pm, β = 109.65(4)°, wR2 = 0.0649, 730 F2 values for Gd4Co2Mg3 and a = 750.4(2), b = 372.86(6), c = 819.5(2) pm, β = 109.48(3)°, wR2 = 0.0398, 888 F2 values for Tb4Co2Mg3 with 30 variables each. The RE4Co2Mg3 structures are 3 : 1 intergrowth variants of distorted CsCl and AlB2 related slabs of compositions REMg and RECo2. Characteristic structural features (exemplary for Tb4Co2Mg3) are relatively short Tb-Co (271 pm), Co-Co (232 pm) and Mg-Mg (314 pm) distances. The latter are a geometrical constraint of the distortion of the REMg and RECo2 slabs. Chemical bonding analysis (ELF and ECOV data) for Gd4Co2Mg3 reveals strong Gd-Co bonding followed by Mg-Co, while the Mg-Mg interactions can be considered as weak. The Co-Co contacts are only weakly bonding. The bonding and antibonding states are almost filled.

Sign in / Sign up

Export Citation Format

Share Document