Copper-rich Intermetallic Compounds RECu9Cd2(RE = La, Ce, Pr, Nd) with YNi9In2-type Structure

2012 ◽  
Vol 67 (11) ◽  
pp. 1225-1228 ◽  
Author(s):  
Michael Johnscher ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Intermetallic Compounds ◽  
Induction Furnace ◽  
Three Dimensional ◽  
Pair Formation ◽  
Type Structure ◽  
X Ray Diffraction ◽  
X Ray

The YNi9In2-type copper-rich compounds RECu9Cd2 (RE=La, Ce, Pr, Nd) were synthesized directly from the elements in sealed niobium ampoules in an induction furnace and were characterized by powder X-ray diffraction. The structure of PrCu9Cd2 was refined from single-crystal Xray diffractometer data: P4/mbm, a=849.0(3), c=498.2(3) pm, wR2=0.0418, 374 F2 values, 23 variables. The structure has two striking polyhedral motifs: Pr@Cu16Cd4 and Cu2@Cu8Cd4. The packing of these polyhedra describes the whole structure. The copper and cadmium atoms build up a three-dimensional [Cu9Cd2] network with broader ranges of Cu-Cu (246 - 274 pm) and Cu-Cd (272 - 288 pm) distances. The cadmium atoms show segregation through pair formation with Cd-Cd distances of 288 pm.

scholarly journals Intermetallic REPtZn Compounds with TiNiSi-type Structure

2011 ◽  
Vol 66 (7) ◽  
pp. 671-676 ◽  
Author(s):  
Trinath Mishra ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Coordination Number ◽  
High Frequency ◽  
Three Dimensional ◽  
Type Structure ◽  
Rare Earth Compounds ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray

The equiatomic rare earth compounds REPtZn (RE = Y, Pr, Nd, Gd-Tm) were synthesized from the elements in sealed tantalum tubes by high-frequency melting at 1500 K followed by annealing at 1120 K and quenching. The samples were characterized by powder X-ray diffraction. The structures of four crystals were refined from single-crystal diffractometer data: TiNiSi type, Pnma, a = 707.1(1), b = 430.0(1), c = 812.4(1) pm, wR2 = 0.066, 602 F2, 21 variables for PrPt1.056Zn0.944; a = 695.2(1), b = 419.9(1), c = 804.8(1) pm, wR2 = 0.041, 522 F2, 21 variables for GdPt0.941Zn1.059; a = 688.2(1), b = 408.1(1), c = 812.5(1) pm, wR2 = 0.041, 497 F2, 22 variables for HoPt1.055Zn0.945; a = 686.9(1), b = 407.8(1), c = 810.4(1) pm, wR2 = 0.061, 779 F2, 20 variables for ErPtZn. The single-crystal data indicate small homogeneity ranges REPt1±xZn1±x. The platinum and zinc atoms build up three-dimensional [PtZn] networks (265 - 269 pm Pt-Zn in ErPtZn) in which the erbium atoms fill cages with coordination number 16 (6 Pt + 6 Zn + 4 Er). Bonding of the erbium atoms to the [PtZn] network proceeds via shorter RE-Pt distances, i. e. 288 - 293 pm in ErPtZn.

Rare Earth-rich Cadmium Compounds RE4TCd (T = Ni, Pd, Ir, Pt)

2008 ◽  
Vol 63 (9) ◽  
pp. 1127-1130 ◽  
Author(s):  
Falko M. Schappacher ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Single Crystal ◽  
Intermetallic Compounds ◽  
Three Dimensional ◽  
Type Structure ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Cadmium Compounds

New intermetallic compounds RE4TCd (RE = Y, La-Nd, Sm, Gd-Tm, Lu; T = Ni, Pd, Ir, Pt) were synthesized by melting of the elements in sealed tantalum tubes in a highfrequency furnace. They crystallize with the Gd4RhIn-type structure, space group F 4̄3m, Z = 16. The four gadolinium compounds were characterized by single crystal X-ray diffractometer data: a = 1361.7(1) pm, wR2 = 0.062, 456 F2 values, 19 variables for Gd4NiCd; a = 1382.1(2) pm, wR2 = 0.077, 451 F2 values, 19 variables for Gd4PdCd; a = 1363.6(2) pm, wR2 = 0.045, 494 F2 values, 19 variables for Gd4IrCd; a = 1379.0(1) pm, wR2 = 0.045, 448 F2 values, 19 variables for Gd4PtCd. The rare earth atoms build up transition metal-centered trigonal prisms which are condensed via common corners and edges, leading to three-dimensional adamantane-related networks. The cadmium atoms form Cd4 tetrahedra which fill voids left in the prisms’ network.

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

Rare Earth-rich Cadmium Compounds RE23T7Cd4 (T = Co, Ni, Ru, Rh, Ir, Pt)

2009 ◽  
Vol 64 (2) ◽  
pp. 184-188 ◽  
Author(s):  
Frank Tappe ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Single Crystal ◽  
Intermetallic Compounds ◽  
High Frequency ◽  
Three Dimensional ◽  
Type Structure ◽  
Interatomic Distances ◽  
X Ray ◽  
Structure Space

The rare earth-rich intermetallic compounds RE23T7CD4(RE = La-Nd, Sm, Gd, Tb; T = Co, Ni, Ru, Rh, Ir, Pt) were synthesized by melting of the elements in sealed tantalum tubes in a high frequency furnace. They crystallize with the Pr23Ir7Mg4-type structure, space group P63mc, Z = 2. The structures of La23Pt7Cd4 (a = 1025.4(2), c = 2319.5(5) pm, wR2 = 0.0425, 2587 F2, 74 variables), La23Ru6.87(1)Cd4 (a = 1015.0(2), c = 2282.8(4) pm, wR2 = 0.0383, 2459 F2, 75 variables), and Nd23Rh7Cd4 (a = 990.0(2), c = 2239.0(5) pm, wR2 = 0.0507, 2350 F2, 74 variables) were refined from single crystal X-ray diffractometer data. Central structural motifs of the RE23 T7Cd4 compounds are transition metal-centered trigonal prisms of rare earth atoms and Cd4 tetrahedra. The RE6T prisms are condensed via common edges and corners, leading to three-dimensional networks. Typical interatomic distances in the prismatic network and in the Cd4 tetrahedra are 295 - 313 pm La-Pt and 319 - 325 pm Cd-Cd, respectively (examplarily for La23Pt7Cd4)

MgCuAl2-type Intermetallics REPdCd2(RE = Ce, Pr, Nd, Sm)

2012 ◽  
Vol 67 (11) ◽  
pp. 1221-1224 ◽  
Author(s):  
Michael Johnscher ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Intermetallic Compounds ◽  
High Frequency ◽  
Three Dimensional ◽  
Type Structure ◽  
Subsequent Annealing ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Structure Factors

The cadmium-rich intermetallic compounds REPdCd2 (RE=Ce, Pr, Nd, Sm) were obtained by high-frequency melting of the elements in sealed niobium ampoules and subsequent annealing in muffle furnaces. The REPdCd2 phases crystallize with the orthorhombic MgCuAl2-type structure, space group Cmcm. The structure of NdPdCd2 was refined from single-crystal X-ray diffractometer data: a=421.9(3), b=995.4(7), c=834.5(6) pm, wR=0.0286, 451 structure factors, 16 variables. The palladium and cadmium atoms build up a three-dimensional [PdCd2] network (281 - 283 pm Pd-Cd; 298 - 335 pm Cd-Cd) in which the neodymium atoms fill cavities. They are connected to the [PdCd2] network via shorter Nd-Pd bonds of 286 pm.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

Ternary Antimonides RE4T7Sb6 (RE=Gd–Lu; T =Ru, Rh) with Cubic U4Re7Si6-type Structure

2013 ◽  
Vol 68 (9) ◽  
pp. 971-978 ◽  
Author(s):  
Inga Schellenberg ◽  
Ute Ch. Rodewald ◽  
Christian Schwickert ◽  
Matthias Eul ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Moment ◽  
Induction Furnace ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Arc Melting ◽  
Intermediate Valent

The ternary antimonides RE4T7Sb6 (RE=Gd-Lu; T =Ru, Rh) have been synthesized from the elements by arc-melting and subsequent annealing in an induction furnace. The samples have been characterized by powder X-ray diffraction. Four structures were refined on the basis of single-crystal X-ray diffractometer data: U4Re7Si6 type, space group Im3m with a=862.9(2) pm, wR2=0.0296, 163 F2 values for Er4Ru7Sb6; a=864.1(1) pm, wR2=0.1423, 153 F2 values for Yb4Ru7Sb6; a=872.0(2) pm, wR2=0.0427, 172 F2 values for Tb4Rh7Sb6; and a=868.0(2) pm, wR2=0.0529, 154 F2 values for Er4Rh7Sb6, with 10 variables per refinement. The structures have T1@Sb6 octahedra and slightly distorted RE@T26Sb6 cuboctahedra as building units. The distorted cuboctahedra are condensed via all trapezoidal faces, and this network leaves octahedral voids for the T1 atoms. The ruthenium-based series of compounds was studied by temperature-dependent magnetic susceptibility measurements. Lu4Ru7Sb6 is Pauli-paramagnetic. The antimonides RE4Ru7Sb6 with RE=Dy, Ho, Er, and Tm show Curie-Weiss paramagnetism. Antiferromagnetic ordering occurs at 10.0(5), 5.1(5) and 4.0(5) K for Dy4Ru7Sb6, Ho4Ru7Sb6 and Er4Ru7Sb6, respectively, while Tm4Ru7Sb6 remains paramagnetic. Yb4Ru7Sb6 is an intermediate-valent compound with a reduced magnetic moment of 3.71(1) μB per Yb as compared to 4.54 μB for a free Yb3+ ion

scholarly journals X-Ray Single Crystal Structural Analysis of Magnetically Oriented Microcrystals

2014 ◽  
Vol 70 (a1) ◽  
pp. C1138-C1138
Author(s):  
Chiaki Tsuboi ◽  
Kazuki Aburaya ◽  
Shingo Higuchi ◽  
Fumiko Kimura ◽  
Masataka Maeyama ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Single Crystal ◽  
Three Dimensional ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Data Set ◽  
Uv Curable ◽  
X Ray

We have developed magnetically oriented microcrystal array (MOMA) technique that enables single crystal X-ray diffraction analyses from microcrystalline powder. In this method, microcrystals suspended in a UV-curable monomer matrix are there-dimensionally aligned by special rotating magnetic field, followed by consolidation of the matrix by photopolymerization. From thus achieved MOMAs, we have been succeeded in crystal structure analysis for some substances [1, 2]. Though MOMA method is an effective technique, it has some problems as follows: in a MOMA, the alignment is deteriorated during the consolidation process. In addition, the sample microcrystals cannot be recovered from a MOMA. To overcome these problems, we performed an in-situ X-ray diffraction measurement using a three-dimensional magnetically oriented microcrystal suspension (3D MOMS) of L-alanine. An experimental setting of the in-situ X-ray measurement of MOMS is schematically shown in the figure. L-alanine microcrystal suspension was poured into a glass capillary and placed on the rotating unit equipped with a pair of neodymium magnets. Rotating X-ray chopper with 10°-slits was placed between the collimator and the suspension. By using this chopper, it was possible to expose the X-ray only when the rotating MOMS makes a specific direction with respect to the impinging X-ray. This has the same effect as the omega oscillation in conventional single crystal measurement. A total of 22 XRD images of 10° increments from 0° to 220° were obtained. The data set was processed by using conventional software to obtain three-dimensional molecular structure of L-alanine. The structure is in good agreement with that reported for the single crystal. R1 and wR2 were 6.53 and 17.4 %, respectively. RMSD value between the determined molecular structure and the reported one was 0.0045 Å. From this result, we conclude that this method can be effective and practical to be used widely for crystal structure analyses.

scholarly journals CRYSTAL STRUCTURE OF THE NEW SILICIDE Lu3Ni11.74(2)Si4

2020 ◽  
Vol 86 (5) ◽  
pp. 3-12
Author(s):  
Bohdana Belan ◽  
Mykola Manyako ◽  
Mariya Dzevenko ◽  
Dorota Kowalska ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Arc Melting ◽  
Pearson Symbol ◽  
Ternary Silicide

The new ternary silicide Lu3Ni11.74(2)Si4 was synthesized from the elements by arc-melting and its crystal structure was determined by the single-crystal X-ray diffraction. The compound crystallizes in the Sc3Ni11Ge4-type: Pearson symbol hP37.2, space group P63/mmc (No. 194), a = 8.0985(16), c = 8.550(2) Å, Z = 2; R = 0.0244, wR = 0.0430 for 244 reflections. The silicide Lu3Ni11.74(2)Si4 is new member of the EuMg5.2-type structure family.

Die neuen Oxobismutate(III) Cs6Bi4O9, K9Bi5O13 und A2Bi4O7 (A = Rb, Cs) / The New Oxobismutates(III) Cs6Bi4O9, K9Bi5O13 and A2Bi4O7 (A = Rb, Cs)

2002 ◽  
Vol 57 (10) ◽  
pp. 1090-1100
Author(s):  
Franziska Emmerling ◽  
Caroline Röhr
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Alkali Metals ◽  
Mixed Valence ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Mixed Valence Compound

AbstractThe title compounds were synthesized at a temperature of 700 °C via oxidation of elemental Bi with the hyperoxides AO2 or via reaction of the elemental alkali metals A with Bi2O3. Their crystal structures have been determined by single crystal x-ray diffraction. They are dominated by two possible surroundings of Bi by O, the ψ-trigonal-bipyramidal three (B) and the ψ-tetrahedral four (T) coordination. Cs6Bi4O9 (triclinic, spacegroup P1̄, a = 813.82(12), b = 991.60(14), c = 1213.83(18) pm, α = 103.658(2), β = 93.694(3), γ = 91.662(3)°, Z = 2) contains centrosymmetric chain segmentes [Bi8O18]12- with six three- (T) and two four-coordinated (B) Bi(III) centers. K9Bi5O13 (monoclinic, spacegroup P21/c, a = 1510.98(14), b = 567.59(5), c = 2685.6(2) pm, β = 111.190(2)°, Z = 4) is a mixed valence compound with isolated [BivO4]3- tetrahedra and chains [BiIII4O9]6- of two T and two B coordinated Bi. In the compounds A2Bi4O7 (A = Rb/Cs: monoclinic, C2/c, a = 2037.0(3) / 2130.6(12), b = 1285.5(2) / 1301.9(7), c = 1566.6(2) / 1605.6(9) pm, β = 94.783(3) / 95.725(9)°, Z = 8) ribbons [Bi4O6O2/2]2- are formed, which are condensed to form a three-dimensional framework.

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