Neue Strukturverfeinerung und Eigenschaften von Cr3C2/Structure Refinement and Properties of Cr3C2

2003 ◽  
Vol 58 (9) ◽  
pp. 929-933 ◽  
Author(s):  
Jochen Glaser ◽  
Ruth Schmitt ◽  
H.-Jürgen Meyer

Cr3C2 was obtained from arc-melting of pellets made of carbon and chromium. The structure of Cr3C2 was determined by single crystal X-ray diffraction (Pnma, Z = 4, a = 553.99(6), b = 283.27(4), c = 1149.4(1) pm, R1 = 0.019 and wR2 = 0.037 for all collected reflections). The crystal structure contains isolated carbon atoms which reside inside of trigonal prismatic voids of metal atoms. The compound exhibits temperature independent paramagnetism. The electronic structure of Cr3C2 has been investigated using extended Hückel calculations.

Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen

The crystal structure redetermination of Sr2PdO3 (distrontium palladium trioxide) was carried out using high-quality single-crystal X-ray data. The Sr2PdO3 structure has been described previously in at least three reports [Wasel-Nielen & Hoppe (1970). Z. Anorg. Allg. Chem. 375, 209–213; Muller & Roy (1971). Adv. Chem. Ser. 98, 28–38; Nagata et al. (2002). J. Alloys Compd. 346, 50–56], all based on powder X-ray diffraction data. The current structure refinement of Sr2PdO3, as compared to previous powder data refinements, leads to more precise cell parameters and fractional coordinates, together with anisotropic displacement parameters for all sites. The compound is confirmed to have the orthorhombic Sr2CuO3 structure type (space group Immm) as reported previously. The structure consists of infinite chains of corner-sharing PdO4 plaquettes interspersed by SrII atoms. A brief comparison of Sr2PdO3 with the related K2NiF4 structure type is given.


2020 ◽  
Vol 86 (5) ◽  
pp. 3-12
Author(s):  
Bohdana Belan ◽  
Mykola Manyako ◽  
Mariya Dzevenko ◽  
Dorota Kowalska ◽  
Roman Gladyshevskii

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.


2007 ◽  
Vol 62 (4) ◽  
pp. 613-616 ◽  
Author(s):  
Wilfried Hermes ◽  
Ute Ch. Rodewald ◽  
Bernard Chevalier ◽  
Rainer Pötgena

The intermetallic cerium compounds CePdGe, CePtSi, and CePtGe were synthesized from the elements by arc-melting and subsequent annealing. The structure of CePtSi was refined from single crystal X-ray diffraction data: LaPtSi-type (ordered α-ThSi2 version), 141md, a = 419.6(1) and c = 1450.0(5) pm, wR2 = 0.0490, 362 F2 values and 16 variables. The Pt-Si distances within the three-dimensional [PtSi] network are 242 pm, indicating strong Pt-Si interactions. Hydrogenation of the three compounds at 623 K and 4 MPa H2 gave no indication for hydride formation.


Author(s):  
Srinivasa Thimmaiah ◽  
Zachary Tener ◽  
Tej N. Lamichhane ◽  
Paul C. Canfield ◽  
Gordon J. Miller

AbstractThe γ-region of the Mn–Al phase diagram between 45 and 70 at.% Al was re-investigated by a combination of powder and single crystal X-ray diffraction as well as EDS analysis to establish the distribution of Mn and Al atoms. Single crystals of γ-Mn


Author(s):  
Hidetomo Hongu ◽  
Akira Yoshiasa ◽  
Massimo Nespolo ◽  
Tsubasa Tobase ◽  
Makoto Tokuda ◽  
...  

Petzite, Ag3AuTe2, crystallizes in the space group I4132, which is a Sohncke type of space group where chiral crystal structures can occur. The structure refinement of petzite reported long ago [Frueh (1959). Am. Mineral. 44, 693–701] did not provide any information about the absolute structure. A new single-crystal X-ray diffraction refinement has now been performed on a sample from Lake View Mine, Golden Mile, Kalgoorlie, Australia, which has resulted in a reliable absolute structure [a Flack parameter of 0.05 (3)], although this corresponds to the opposite enantiomorph reported previously. The minimum Te–Te distance is 3.767 (3) Å, slightly shorter than the van der Waals bonding distance, which suggests a weak interaction between the two chalcogens. XANES spectra near the Au and Te L III edges suggest that the chemical-bonding character of Au in petzite is more metallic than in other gold minerals.


2008 ◽  
Vol 41 (3) ◽  
pp. 584-591 ◽  
Author(s):  
Jiandong Fan ◽  
Huaijin Zhang ◽  
Wentao Yu ◽  
Haohai Yu ◽  
Jiyang Wang ◽  
...  

A transparent Yb3+:NaY(WO4)2single crystal with dimensions of 30 mm (diameter) × 40 mm has been grown by the Czochralski method. The high crystalline quality of the as-grown Yb3+:NaY(WO4)2crystals was confirmed by high-resolution X-ray diffraction. The effective segregation coefficients of elemental Yb, Na, Y and W in Yb3+:NaY(WO4)2were measured using the X-ray fluorescence method. Powder and single-crystal X-ray diffraction data of NaYb0.05Y0.95(WO4)2are reported. The structure refinement shows that NaYb0.05Y0.95(WO4)2crystallizes in the tetragonal space groupI41/a, witha=b= 5.2039 (2),c= 11.2838 (9) Å, α = β = γ = 90°,V= 305.57 (3) Å3andZ= 2. A series of possible growth faces (hkl) were determined from the crystal lattice and symmetry according to the Bravais–Friedel Donnay–Harker theory, and the relationship among crystal structure, growth habits and crystal morphology is discussed. In addition, the thermal properties of the crystal, including the specific heat, thermal expansion, thermal diffusion and thermal conductivity, were carefully investigated. The anisotropy of the crystal thermal conductivities is explained from the point of view of the crystal structure.


1986 ◽  
Vol 41 (8) ◽  
pp. 935-937 ◽  
Author(s):  
Franz A. Mautner ◽  
Harald Krischner ◽  
Christoph Kratky

Abstract The crystal structure of [Mg(H2O)6](N3)2 was determined by single crystal X-ray diffraction (421 independent observed MoKα-counter reflections. R = 0.037). The crystals are orthorhombic, space group Fmmm, Z = 4, a = 644.3(1), b = 1134.4(1), c = 1333.5(3) pm. The magnesium atoms are octahedrally coordinated to six oxygen atom s of water molecules, the azide groups are not coordinated to metal atoms, N -N = 117.0(2) pm.


2019 ◽  
Vol 74 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Nataliya Gulay ◽  
Yuriy Tyvanchuk ◽  
Marek Daszkiewicz ◽  
Bohdan Stel’makhovych ◽  
Yaroslav Kalychak

AbstractTwo compounds in the Sc-Co-In system were obtained by arc-melting of the pure metals and their crystal structures have been determined using single crystal X-ray diffraction data. The structure of Sc3Co1.64In4 (space group P6̅, а=7.6702(5), c=3.3595(2) Å, Z=1, R1=0.0160, wR2=0.0301) belongs to the Lu3Co2−xIn4 type structure, which is closely related to the ZrNiAl and Lu3CoGa5 types. The structure of Sc10Co9In20 (space group P4/nmm, а=12.8331(1), c=9.0226(1) Å, Z=2, R1=0.0203, wR2=0.0465) belongs to the Ho10Ni9In20 type, which is closely related to HfNiGa2.


2015 ◽  
Vol 70 (7) ◽  
pp. 497-503 ◽  
Author(s):  
Nataliya Dominyuk ◽  
Vasyl’ I. Zaremba ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen

AbstractThe ternary indide Nd39Ir10.98In36.02 was synthesized by arc-melting and characterized by single crystal X-ray diffraction. Nd39Ir10.98In36.02 crystallizes with a new structure type: Pearson code oP172, Pbam, a = 3175.4(6), b = 3762.5(8), c = 378.02(8) pm, wR2 = 0.0828, 5544 F2 values, and 262 variables. Although the structure contains 44 crystallographically independent sites, it can easily be explained as an intergrowth structure of CsCl and AlB2 related slabs. The larger indium atoms fill all distorted CsCl slabs. The trigonal prismatic (AlB2) slabs have no uniform size. The larger ones are filled by indium and the smaller ones by the iridium atoms. Additionally, one trigonal prism shows a mixed occupancy by indium and iridium. The crystal chemistry of Nd39Ir10.98In36.02 is discussed in the context of other intergrowth structures with the same simple slabs.


2021 ◽  
Vol 76 (3-4) ◽  
pp. 243-247
Author(s):  
Bohdana Belan ◽  
Tamara J. Bednarchuk ◽  
Vasyl Kinzhybalo ◽  
Mariya Dzevenko ◽  
Svitlana Pukas ◽  
...  

Abstract The intermetallic compound LaNi11.8–11.4Si1.2–1.6 was synthesized by arc-melting and its crystal structure was determined using powder and single-crystal X-ray diffraction data. The compound adopts the cubic CaCu6.5Al6.5-type structure (space group Fm 3 ‾ $\bar{3}$ c, Pearson code cF112, Z = 8), which is a partially ordered ternary derivative of the NaZn13 type: a = 11.256(4) Å, V = 1426.1(15) Å3, R = 0.0133, wR = 0.0285 for 93 reflections with I > 2 σ(I) for LaNi11.4Si1.6; a = 11.25486(8) Å, V = 1425.68(2) Å3, R p = 4.17%, R wp = 5.85%, R B = 3.44% for LaNi11.8Si1.2. One of its crystallographic positions (96i) is occupied by a mixture of Ni and Si atoms. The structure of this new silicide can be represented as a packing of Ni-centered icosahedra and La-centered snub cubes, which are packed in a CsCl-related manner.


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