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The new compound Yb2+3—xPd12—3+xP7x = 0.40(4)) was synthesized by sintering of a mixture of elemental components at 1100 °C with subsequent annealing at 800 °C. The crystal structure of Yb2+3—xPd12—3+xP7 was solved and refined from X-ray single-crystal diffraction data: space group P6¯, a = 10.0094(4)A, c = 3.9543(2)A, Z = 1; R(F) = 0.022 for 814 observed unique reflections and 38 refined parameters. The atomic arrangement reproduces a structure motif of the hexagonal Zr2Fe12P7 type in which one of the transition metal positions is substituted predominantly by ytterbium (Yb : Pd = 0.86(1) : 0.14). The ytterbium atoms are embedded in the 3D polyanion formed by palladium and phosphorus atoms. Two different environments for ytterbium atoms are present in the structure. Magnetic susceptibility measurements and XAS spectroscopy at the Yb LIII edge show the presence of ytterbium in two electronic configurations, 4ƒ13 and 4ƒ14. The following model was derived. Ytterbium atoms in the 3k site are in the 4ƒ13 state, the two remaining positions contain ytterbium in intermediate-valence states, giving totally 79 % ytterbium in the 4ƒ13 electronic configuration. Yb2+3—xPd12—3+xP7 (x = 0.40): verschiedene Ytterbium-Spezies in einem Substitutionsmotiv des Zr2Fe12P7-Strukturtyps Eine neue Verbindung Yb2+3—xPd12—3+xP7 (x = 0.40(4)) wurde durch Sintern der Elementmischung bei 1100 °C mit anschliesendem Tempern bei 800 °C dargestellt. Die Kristallstruktur von Yb2+3—xPd12—3+xP7 wurde aus Einkristall-Daten ermittelt und verfeinert: Raumgruppe P6¯, a = 10.0094(4)A, c = 3.9543(2)A, Z = 1; R(F) = 0.022 fur 814 Reflexe und 38 Variablen. Die Atomanordnung in der Struktur von Yb2+3—xPd12—3+xP7 gibt das Motiv des hexagonalen Zr2Fe12P7-Typs wieder, wobei jedoch eine der Ubergangs-Metall-Positionen uberwiegend mit Ytterbium besetzt wird (Yb : Pd = 0.86(1) : 0.14). Die Ytterbium-Atome sind in einem dreidimensionalen Polyanion aus Palladium- und Phosphor-Atomen eingebettet. Das Existenz von zwei verschiedenen Umgebungen fur Ytterbium in der Struktur wurde durch Messungen der magnetischen Suszeptibilitat und durch XAS-Spektroskopie bestatigt. Beide zeigen Ytterbium in zwei elektronischen Konfigurationen, 4ƒ13 und 4ƒ14. Die Ergebnisse lassen sich mit einem Model beschreiben, in dem die Ytterbium-Atome zum einen die 4ƒ13-Konfiguration (Wyckoff-Lage 3k) und zum anderen eine zwischenvalente Konfiguration aufweisen. Daraus resultiert eine 4ƒ13-Konfiguration fur insgesamt 79 % des Ytterbiums.

Jede Menge Lithium: Die Silicide Li7CuSi2, mit dem linearen Zintl-Anion [Si-Cu-Si]7− (siehe Bild), und Li7.3CuSi3 sind die Verbindungen mit dem hochsten Lithiumgehalt in diesem ternren System. Die Kristallstrukturen und Bindungsverhltnisse beider Verbindungen werden besprochen.

Materials with a low degree of space filling may have low thermal conductivity. If combined with the enhanced thermopower, often observed in strongly correlated rare-earth or transition metal containing materials, this may result in a material with superior thermoelectric properties for cooling applications. YbGa6Te10 is a new rare-earth containing material. The thermal conductivity of this compound is very low and is explained in terms of low degree of space filling, large unit cell and relatively heavy elements. The very low thermal conductivity makes this compound or similar modifications a potential candidate for a strongly correlated thermoelectric material.

The new compounds Li7CuSi2 (I) and Li7.3CuSi3 (II) are synthesized from the elements (Nb ampule, 600 °C, 7 d) and characterized by XRD, magnetic measurements, and band structure calculations.

A new phase, Sn(x)Pt4Sb(12-y)Sn(y), has been prepared from the elements. It exhibits a wide range of homogeneity with 0.3(2) < or = x < or = 1.0(2) and 4.2(2) < or = y < or = 7.0(2). The crystal structure and the composition were established by single-crystal and powder X-ray diffraction as well as wavelength-dispersive X-ray analysis measurements and were supported by nuclear magnetic resonance experiments. The compound is the first representative of the filled-skutterudite family with the filler atoms not located at the center of the cavity but covalently bonded to the cavity's wall, as confirmed by the analysis of chemical bonding with the electron localizability indicator. The Sn and Sb atoms share the framework site with different coordinate parameters caused by the difference in atomic size; additional tin atoms are located in the cavities of the framework. The material is a diamagnet in the whole composition range. In agreement with the calculated electronic density of states, the material reveals a metallic behavior in electronic transport. The absolute values of electrical resistivity vary with the tin-to-antimony ratio.

The title compound was prepared from elements by sintering in the temperature region between 1073 and 1473 K. The monoclinic structure of La 7 Pd 1 7 P 1 2 was solved and refined from X-ray single crystal data: space group C2/m, a = 24.519(1), b = 4.0859(5), c = 13.6106(8) A,β = 112.129(3)°, Z = 2, R F = 0.025 for 1065 unique of 4877 measured reflections and 112 refined parameters. Main structural motif of the new phosphide are condensed blocks of trigonal prisms around phosphorus atoms connected to infinite chains via lanthanum atoms. The structural features of La 7 Pd 1 7 P 1 2 are discussed in comparison with some representatives of a large family of structures with metal / non-metal ratio close to 2: 1.