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  • 1
    ISSN: 1434-1948
    Schlagwort(e): Europium ; Ytterbium ; Indium ; Intermetallic compounds ; Ferromagnetism ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The new compounds EuPdIn2 (1), YbPdIn2 (2), and YbAuIn2 (3) have been synthesized by high-frequency melting of the elements in sealed tantalum tubes and subsequent annealing at about 900 K. Their crystal structures have been determined by single-crystal X-ray diffraction techniques. Compounds 1, 2, and 3 crystallize with the MgCuAl2-type structure (space group Cmcm), a ternary ordered version of the Re3B type. Structural elements in these compounds are transition metal centered trigonal prisms made up of the rare earth and indium atoms. The transition metal (T) and indium atoms form a three-dimensionally infinite [TIn2] polyanionic network in which the large rare earth metal atoms occupy one-dimensional pentagonal tubes. A semiempirical band structure calculation on 1 reveals a non-vanishing density-of-states (DOS) at the Fermi level. The strongest bonding interactions are found for the In-In and Pd-In contacts; the Eu-Pd and Eu-In interactions are much weaker. Magnetic investigations indicate divalent character of the ytterbium atoms in 2, showing negative susceptibilities below room temperature. Compound 1 exhibits Curie-Weiss behavior above 50 K with an experimental magnetic moment of 7.8(1) μB, thus indicating divalent europium. Ferromagnetic ordering was observed at TC = 14.5(5) K, with a saturation moment of 6.8(1) μB/Eu at 5.5 T and 4 K, as determined from magnetization measurements. Compounds 1 and 2 are found to be metallic conductors.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Chemistry - A European Journal 2 (1996), S. 800-804 
    ISSN: 0947-6539
    Schlagwort(e): crystal structure ; electronic structure ; hafnium compounds ; indium compounds ; metallic conductivity ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Hf2In5 - previously reported with the tentative composition “Hf3In4” - was prepared from the elements in a tantalum tube at 970 K. The X-ray diffractional characterization by means of single-crystal refinement reveals the presence of a tetragonal structure (a = 1024.71 (9), c = 305.66 (3) pm, P4/mbm, Z = 2) of Mn2Hg5 type. Hf2In5 is Pauli-paramagnetic and a good metallic conductor. Quasi-relativistic semiempirical and scalar-relativistic ab initio band structure calculations reveal Hf2In5 to be a hafnide, composed of a two-dimensional indium network threaded by infinite hafnium chains. The amount of In-In bonding scales counterintuitively with the interatomic distances.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 0044-2313
    Schlagwort(e): β-Li3TiF6 ; crystal structure ; band structure ; Jahn Teller effect ; magnetism ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Darstellung, Kristallstruktur und magnetische Eigenschaften von β-Li3TiF6 = Li2[4]Li7[6](TiF6)(TiF6)2 - ein Doppelfluorid?Purpurfarbene Einkristalle von β-Li3TiF6 wurden durch Erhitzen eines Gemenges von LiF und TiF3 (3 : 1) bei 820°C unter Argon erhalten. β-Li3TiF6 kristallisiert in C2/c mit a = 14.452(2) Å, b = 8.798(1) Å, c = 10.113(1) Å und β = 96.30(1)º. Die Struktur ist isotyp mit β-Li3VF6 und enthält isolierte gestauchte TiF6-Oktaeder (dTi-F = 1.91-2.01 Å). Die magnetischen Eigenschaften von β-Li3TiF6 untersucht und diskutiert. Die Bindungsverhältnisse werden anhand von Bandstruktur Rechnungen und Berechnungen des Madelunganteils der Gitterenergie, MAPLE, diskutiert.
    Notizen: Purple colored single crystals of the β-modification of Li3TiF6 have been prepared by heating an appropriate mixture of LiF and TiF3 at 820°C under an argon atmosphere. β-Li3TiF6 crystallizes in C2/c with a = 14.452(2) Å, b = 8.798(1) Å, c = 10.113(1) Å and β = 96.30(1)º. The structure is isotypic to β-Li3VF6 and contains isolated compressed TiF6 octahedra (dTi-F = 1.91-2.01 Å). Magnetic properties of β-Li3TiF6 were studied and discussed. Band structure calculations and calculations of the Madelung part of the lattice energy, MAPLE, were performed to discuss the chemical bonding.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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