Yb5Ni4Sn10 and Yb7Ni4Sn13: New polar intermetallics with 3D framework structures

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. Yb 5 Ni 4 Sn 10 adopts the Sc 5 Co 4 Si 10 structure type and crystallizes in the tetragonal space group P 4 /mbm (No. 127) with cell parameters of a =13.785(4) A, c =4.492 (2) A, V=853.7(5) A 3 , and Z =2. Yb 7 Ni 4 Sn 13 is isostructural with Yb 7 Co 4 InGe 12 and crystallizes in the tetragonal space group P 4 /m (No. 83) with cell parameters of a =11.1429(6) A, c =4.5318(4) A, V=562.69(7) A 3 , 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.