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Abstract: K2Mg5−x Sn3 (x=0.28) and K3Mg18 Tt 11 (Tt=Sn, Pb) have been synthesized by reacting the mixture of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction studies. K2Mg5−x Sn3 (x=0.28) is isostructural with Ni7−x SbQ 2 (Q=Se, Te) series and features 2D corrugated [Mg5−x Sn3] layers that are separated by K+ cations. The structure of K3Mg18 Tt 11 (Tt=Sn, Pb) is closely related to the Ho2Rh12As7 structural type and features 3D [Mg18 Tt 11] framework composed of 1D [Mg18 Tt 11] columns that are interconnected via Mg–Tt bonds, forming 1D hexagonal tunnels occupied by the K+ cations. Electronic structure calculations indicate that Mg atoms can function as either electron donor or as a participator in the network along with Tt atoms. Magnetic property measurements and band structure calculations indicate that these compounds are metallic. [Copyright &y& Elsevier]

Abstract: Four new isostructural rare earth manganese stannides, namely RE 3MnSn5−x (x=0.16(6), 0.29(1) for RE=Tm, x=0.05(8), 0.21(3) for RE=Lu), have been obtained by reacting the mixture of corresponding pure elements at high temperature. Single-crystal X-ray diffraction studies revealed that they crystallized in the orthorhombic space group Pnma (No. 62) with cell parameters of a=18.384(9)–18.495(6)Å, b=6.003(3)–6.062(2)Å, c=14.898(8)–14.976(4)Å, V=1644.3(14)–1679.0(9)Å3 and Z=8. Their structures belong to the Hf3Cr2Si4 type and feature a 3D framework composed of 1D [Mn2Sn7] chains interconnected by [Sn3] double chains via Sn–Sn bonds, forming 1D large channels based on [Mn4Sn16] 20-membered rings along the b-axis, which are occupied by the rare earth atoms. Electronic structure calculations based on density functional theory (DFT) for idealized “RE3MnSn5” model indicate that these compounds are metallic, which are in accordance with the results from temperature-dependent resistivity measurements. [ABSTRACT FROM AUTHOR]

Abstract: The title compounds have been obtained by solid state reactions of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction studies. Yb5Ni4Sn10 adopts the Sc5Co4Si10 structure type and crystallizes in the tetragonal space group P4/mbm (No. 127) with cell parameters of a=13.785(4)Å, c=4.492 (2)Å, V=853.7(5)Å3, and Z=2. Yb7Ni4Sn13 is isostructural with Yb7Co4InGe12 and crystallizes in the tetragonal space group P4/m (No. 83) with cell parameters of a=11.1429(6)Å, c=4.5318(4)Å, V=562.69(7)Å3, and Z=1. Both structures feature three-dimensional (3D) frameworks based on three different types of one-dimensional (1D) channels, which are occupied by the Yb atoms. Electronic structure calculations based on density functional theory (DFT) indicate that both compounds are metallic. These results are in agreement with those from temperature-dependent resistivity and magnetic susceptibility measurements. [Copyright &y& Elsevier]

Abstract: A new rare earth nickel stannide, Sm2NiSn4, has been prepared by reacting the pure elements at high temperature in welded tantalum tubes. Its crystal structure was established by single crystal X-ray diffraction studies. Sm2NiSn4 crystallizes in the orthorhombic space group Pnma (No. 62) with cell parameters of a=16.878(2)Å, b=4.4490(7)Å, c=8.915(1)Å, and Z=4. Its structure can be viewed as the intermediate type between ZrSi2 and CeNiSi2. Sm2NiSn4 features two-dimensional (2D) corrugated [NiSn4]6− layers in which the 1D Sn zigzag chains and the 2D Sn square sheets are bridged by Ni atoms. The Sm3+ cations are located at the interlayer space. Results of both resistivity measurements and extended-Hückel tight-binding band structure calculations indicate that Sm2NiSn4 is metallic. [Copyright &y& Elsevier]