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.

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.

GdCuMg with ZrNiAl-type structure – an 82.2 K ferromagnet

2017 ◽  
Vol 72 (7) ◽  
pp. 511-515 ◽  
Author(s):  
Sebastian Stein ◽  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Moment ◽  
Type Structure ◽  
Induction Melting ◽  
X Ray Diffraction ◽  
Muffle Furnace ◽  
Temperature Dependent ◽  
X Ray ◽  
Experimental Magnetic Moment

AbstractGdCuMg has been synthesized by induction-melting of the elements in a sealed niobium ampoule followed by annealing in a muffle furnace. The sample was studied by powder and single crystal X-ray diffraction: ZrNiAl type, P6̅2m (a=749.2(4), c=403.3(1) pm), wR2=0.0242, 315 F2 values and 15 variables. Temperature dependent magnetic susceptibility measurements have revealed an experimental magnetic moment of 8.54(1) μB per Gd atom. GdCuMg orders ferromagnetically below TC=82.2(5) K and based on the magnetization isotherms it can be classified as a soft ferromagnet.

The Stannides EuPdSn and EuPtSn

1996 ◽  
Vol 51 (6) ◽  
pp. 806-810 ◽  
Author(s):  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Three Dimensional ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

Abstract EuPdSn and EuPtSn were prepared from the elements in tantalum tubes at 1070 K and investigated by X-ray diffraction on both powder as well as single crystals. They crystallize with the TiNiSi type structure of space group Pnma and with Z = 4 formula units per cell. Both structures were refined from single-crystal diffractometer data: a = 751.24(9), b = 469.15(6), c = 804.31(9) pm, V = 0.2835(1) nm3 for EuPdSn, and a = 753.38(7), b = 467.72(4), c = 793.08(7) pm, V = 0.2795(1) nnr for EuPtSn. The structures consist of three-dimensional [PdSn] and [PtSn] polyanionic networks in which the europium atoms are embedded. The crystal chemistry of these stannides is briefly discussed

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.

Indides RE3T2In4 (RE = Y, Gd–Tm, Lu; T = Ni, Ru, Rh) with a ZrNiAl superstructure

2016 ◽  
Vol 71 (12) ◽  
pp. 1261-1267 ◽  
Author(s):  
Birgit Heying ◽  
Oliver Niehaus ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Transition Metals ◽  
Single Crystal ◽  
Symmetry Reduction ◽  
Type Structure ◽  
Crystal Chemical ◽  
Space Group ◽  
X Ray ◽  
Structure Space

AbstractThree series of rare earth-transition metal-indides RE3T2In4 (RE=Y, Gd–Tm, Lu; T=Ni, Ru, Rh) were synthesized from arc-melted RE3T2 precursor compounds and indium tear shot in sealed niobium ampoules using different annealing sequences. The new indides crystallize with the hexagonal Lu3Co2In4-type structure, space group P6̅. All samples were characterized on the basis of Guinier powder patterns and six structures were refined from single crystal X-ray diffractometer data. The RE3T2In4 structures are derived from the ZrNiAl type through RE/In ordering, paralleled by a symmetry reduction from P6̅2m to P6̅. This induces twinning for some of the investigated crystals. The main crystal chemical motifs of the RE3T2In4 structures are trigonal prisms of rare earth, respectively indium atoms that are filled by the transition metals.

La5Ir1.73In4.27 with Lu5Ni2In4-type structure

2020 ◽  
Vol 75 (6-7) ◽  
pp. 709-713
Author(s):  
Nataliya Dominyuk ◽  
Vasyl’ I. Zaremba ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Small Degree ◽  
Type Structure ◽  
Muffle Furnace ◽  
Space Group ◽  
One Dimensional ◽  
X Ray ◽  
Structure Space ◽  
Arc Melting

AbstractSingle crystals of La5Ir1.73In4.27 were grown from a sample of the starting composition 47La: 17Ir: 36 In by arc-melting, followed by a long annealing sequence in a muffle furnace. La5Ir1.73In4.27 crystallizes with the Lu5Ni2In4-type structure, space group Pbam, which was refined from single-crystal X-ray diffractometer data: a = 834.0(2), b = 1862.2(4), c = 385.31(8) pm, wR2 = 0.0278, 1165 F2 values and 37 variables. The 4h iridium site shows a small degree of Ir/In mixing. Geometrically one can describe the La5Ir1.73In4.27 structure as a simple 4:1 intergrowth variant of CsCl and AlB2-related slabs. The iridium and indium atoms form a one-dimensional meandering [Ir1.73In4.27]δ– polyanion (292 pm Ir–In and 327 pm In–In) which is embedded in a lanthanum matrix.

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.

The scandium-rich indide Sc50Pt13.47In2.53

2020 ◽  
Vol 75 (6-7) ◽  
pp. 715-720 ◽  
Author(s):  
Nataliya L. Gulay ◽  
Jutta Kösters ◽  
Yaroslav M. Kalychak ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Intermetallic Phases ◽  
Subsequent Annealing ◽  
Induction Melting ◽  
X Ray

AbstractThe scandium-rich indide Sc50Pt13.47In2.53 was obtained by induction melting of the elements and subsequent annealing. The structure of Sc50Pt13.47In2.53 has been refined from single-crystal X-ray diffractometer data: Fm$\overline{3}$, a = 1774.61(3) pm, wR2 = 0.0443, 1047 F2 values and 35 variables. Sc50Pt13.47In2.53 is isopointal with the intermetallic phases Sc50Co12.5In3.5, Sc50Rh13.3In2.7, Sc50Ir13.6In2.4, Ag7+xMg26−x and Ga4.55Mg21.85Pd6.6 (Pearson code cF264 and Wyckoff sequence ih2fecba). Two of the eight crystallographic sites in the structure show mixed occupancies: M1 (≡Pt20.70In10.30) and M2 (≡Pt30.76In20.24). The structure contains four basic polyhedra: M2@Sc8 cubes, Pt1@Sc10 sphenocorona and slightly distorted M1@Sc12 and In3@Sc12 icosahedra. The polyhedra are condensed via common scandium corners and edges. The various Sc–Sc distances range from 302–334 pm and are indicative of substantial Sc–Sc bonding, stabilizing the Sc50Pt13.47In2.53 structure.

Strukturvarianten des MgCu2-Typs: Die Verbindungen Mg2Ni3P und Mg2Ni3As / Variants of the MgCu2 Type: The Compounds Mg2Ni3P and Mg2Ni3As

1992 ◽  
Vol 47 (10) ◽  
pp. 1351-1354 ◽  
Author(s):  
Viktor Keimes ◽  
Albrecht Mewis
Keyword(s):  
Single Crystal ◽  
Homogeneity Range ◽  
Hexagonal Lattice ◽  
Structure Type ◽  
Type Structure ◽  
X Ray ◽  
Lattice Constants ◽  
Metal Atoms ◽  
Rhombohedral Symmetry

The compounds Mg2Ni3P and Mg2Ni3As were prepared by heating the elements. Their structures have been determined from single-crystal X-ray data. The structure of the phosphide is a rhombohedral ternary variant of the cubic Laves structure type MgCu2 (R 3̄ m; hexagonal lattice constants: a = 4.971(0) Å, c = 10.961(2) Å). The ordered substitution of one quarter of the metal atoms by phosphorus and the resulting shorter distances are responsible for the rhombohedral symmetry.The arsenide crystallizes in the MgCu2 type structure (Fd 3 m; a = 6.891(1)A, composition Mg2Ni3As) with a statistic distribution of the Ni and As atoms; the relevant homogeneity range extends from Mg2Ni2.9As1.1 to Mg2Ni3.5As0.5.

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