scholarly journals Variants of the X-phase in the Mn–Co–Ge system

2021 ◽  
Vol 77 (4) ◽  
pp. 176-180
Author(s):  
Vitalii Shtender ◽  
Simon R. Larsen ◽  
Martin Sahlberg
Keyword(s):  
Chemical Composition ◽  
Single Crystal ◽  
Intermetallic Compounds ◽  
Energy Dispersive Spectroscopy ◽  
Structure Type ◽  
Homogeneity Region ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Chemical Disorder

We report two new variants of the X-phase (orthorhombic, space group Pnnm) derived from the Mn–Co–Ge system. Two compositionally related crystals were investigated by means of single-crystal X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The Mn14.9Co15.5Ge6.6 and Mn14Co16.2Ge6.8 intermetallic compounds are part of the homogeneity region of the X-phase and adopt the Mn14(Mn0.11Co0.64Si0.25)23 structure type. The composition obtained from refinement of the XRD data is in agreement with the EDS results. In the present study, chemical disorder was only detected on the 8h positions. The ordering is compared with other members of the X-phase family and shows that the degree of disordering depends on the chemical composition. No completely ordered variants of the X-phase have yet been reported.

RE3Au5Zn (RE = Y, Sm, Gd–Ho) – A new structure type with five- and six-membered rings as building units in a gold network

2016 ◽  
Vol 71 (5) ◽  
pp. 411-417 ◽  
Author(s):  
Birgit Gerke ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Intermetallic Compounds ◽  
Diffraction Data ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
The Rare Earth

AbstractRE3Au5Zn (RE = Y, Sm, Gd–Ho) intermetallic compounds were synthesized by melting the elements in sealed tantalum tubes. They exhibit a new structure type which was studied by X-ray diffraction on powders and refined from single crystal diffraction data: Cmcm, a = 736.9(2), b = 1489.4(2), c = 1330.4(3) pm, wR2 = 0.0371, 1184 F2 values and 55 variables for Y3Au4.92Zn1.08 and a = 739.0(1), b = 1495.8(2), c = 1339.2(2) pm, wR2 = 0.0325, 1410 F2 values and 54 variables for Tb3Au5Zn. The network consists of five- and six-membered gold rings in puckered conformations. Atoms of the rare earth elements are placed within the cavities of this network where every third cavity is filled by a Zn2 dumbbell. The structure is discussed in detail and compared with the gold substructure of Hf7Au10.

Die Kristallstrukturen der isotypen Verbindungen Ba3[MoN4] und Ba3[WN4] / The Crystal Structures of the Isotypic Compounds Ba3[MoN4] and Ba3[WN4]

1991 ◽  
Vol 46 (5) ◽  
pp. 566-572 ◽  
Author(s):  
Axel Gudat ◽  
Peter Höhn ◽  
Rüdiger Kniep ◽  
Albrecht Rabenau
Keyword(s):  
Transition Metals ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ternary Compounds ◽  
The Third

The isotypic ternary compounds Ba3[MoN4] and Ba3[WN4] were prepared by reaction of the transition metals with barium (Ba3N2, resp.) under nitrogen. The crystal structures were determined by single crystal X-ray diffraction: Ba3[MoN4] (Ba3[WN4]): Pbca; Z = 8; a = 1083.9(3) pm (1091.8(3) pm), b = 1030.3(3) pm (1037.5(3) pm), c = 1202.9(3) pm (1209.2(4) pm). The structures contain isolated tetrahedral anions [MN4]6- (M = Mo, W) which are arranged in form of slightly distorted hexagonal layers and which are stacked along [010] with the sequence (···AB···). Two of the three Ba atoms are situated between, the third one is placed within the layers of [MN4]-groups. In this way the structures can be derived from the Na3As structure type.

scholarly journals β-Y(BO2)3 – a new member of the β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu) structure family

2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).

scholarly journals Redetermination of Sr2PdO3 from single-crystal X-ray data

2019 ◽  
Vol 75 (1) ◽  
pp. 30-32
Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Structure Type ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters

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.

scholarly journals Redetermination of the crystal structure of RhPb2 from single-crystal X-ray diffraction data, revealing a rhodium deficiency

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Takashi Mochiku ◽  
Yoshitaka Matsushita ◽  
Nikola Subotić ◽  
Takanari Kashiwagi ◽  
Kazuo Kadowaki
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Type ◽  
Site Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters ◽  
Slight Deficiency

RhPb2 (rhodium dilead) is a superconductor crystallizing in the CuAl2 structure type (space group I4/mcm). The Rh and Pb atoms are located at the 4a (site symmetry 422) and 8h (m.2m) sites, respectively. The crystal structure is composed of [RhPb8] antiprisms, which share their square faces along the c axis and the edges in the direction perpendicular to the c axis. We have succeeded in growing single crystals of RhPb2 and have re-determined the crystal structure on basis of single-crystal X-ray diffraction data. In comparison with the previous structure studies using powder X-ray diffraction data [Wallbaum (1943). Z. Metallkd. 35, 218–221; Havinga et al. (1972). J. Less-Common Met. 27, 169–186], the current structure analysis of RhPb2 leads to more precise unit-cell parameters and fractional coordinates, together with anisotropic displacement parameters for the two atoms. In addition and likewise different from the previous studies, we have found a slight deficiency of Rh in RhPb2, leading to a refined formula of Rh0.950 (9)Pb2.

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].

A new ternary silicide GdFe1−xSi2 (x=0.32): preparation, crystal and electronic structure

2020 ◽  
Vol 75 (1-2) ◽  
pp. 217-223
Author(s):  
Volodymyr Babizhetskyy ◽  
Jürgen Köhler ◽  
Yuriy Tyvanchuk ◽  
Chong Zheng
Keyword(s):  
Electronic Structure ◽  
Tight Binding ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Arc Melting ◽  
Lmto Method ◽  
Type Orthorhombic ◽  
Crystal And Electronic Structure

AbstractThe title compound was prepared from the elements by arc-melting. The crystal structure was investigated by means of single-crystal X-ray diffraction. It crystallizes in the TbFeSi2 structure type, orthorhombic space group Cmmm, a = 4.0496(8), b = 16.416(2), c = 3.9527(6) Å, Z = 4, R1 = 0.041, wR2 = 0.11 for 207 unique reflections with Io > 2 σ(Io) and 19 refined parameters. The Fe position is not fully occupied and the refinement results in a composition GdFe0.68Si2 in agreement with a chemical analysis. The structure consists of zig-zag chains of Si(1) atoms which are terminally bound to additional Si(2) atoms. For an ordered variant GdFe0.5Si2 the Zintl concept can be applied which results in formal oxidation states Gd3+(Fe2+)0.5Si(1)1−Si(2)3−. The electronic structure of this variant GdFe0.5Si2 was analyzed using the tight-binding LMTO method and the results confirm the simple bonding picture.

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.

Copper deficiency in UCu5−x Sn [x = 0.37 (1)]

2006 ◽  
Vol 62 (4) ◽  
pp. i106-i108
Author(s):  
Svilen Bobev ◽  
Eric D. Bauer ◽  
John L. Sarrao
Keyword(s):  
Single Crystal ◽  
Title Compound ◽  
Copper Deficiency ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Width

The ternary intermetallic title compound, known hitherto as UCu5Sn (uranium pentacopper stannide), crystallizes with the hexagonal CeNi5Sn structure type, and it has been presumed to be a fully stoichiometric phase, devoid of any disorder. However, the present single-crystal X-ray diffraction studies at 120 K, carried out with crystals grown from an Sn flux, suggest the existence of a previously unnoticed phase width of the title compound UCu5−x Sn. All the atoms occupy special positions: U (\overline{6}m2, \overline{3}m.), Sn (3m.) and Cu (.m., 3m., and two positions with \overline{6}m2).

Microbial Transformation of Glycyrrhetinic Acid by Colletotrichum lini AS3.4486

2015 ◽  
Vol 1120-1121 ◽  
pp. 877-881
Author(s):  
Chao Jun He ◽  
Yu Min Yang ◽  
Kong Yang Wu
Keyword(s):  
Single Crystal ◽  
Microbial Transformation ◽  
Glycyrrhetinic Acid ◽  
Conversion Product ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
H Nmr ◽  
Sole Product ◽  
C Nmr

The biotransformation of 18β-glycyrrhetinic acid by Colletotrichum lini AS3.4486 was investigated. The conversion reaction was carried out for 72h, and the sole product was isolated by column chromatography and elucidated as 7β,15α-dihydroxy-18β-glycyrrhetinic acid by HR-ESI-MS, 1H-NMR , 13C-NMR and single–crystal X-ray diffraction. The crystal of the conversion product belongs to orthorhombic, space group P212121 with 11.828(1), 13.213(2), 19.606(2) Å , V = 3064.0 Å3, Z = 4. This study povides a new method for the synthesis of 7β,15α-dihydroxy-18β-glycyrrhetinic acid.

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