ChemInform Abstract: Syntheses and Structures of Sc₂Nb_4‐xSn₅, YNb₆Sn₆, and ErNb₆Sn₅: Exploratory Studies in Ternary Rare‐Earth Niobium Stannides.

Abstract

Rare-Earth Niobium Stannides. -The new compoundsSc2Nb4-xSn5 (x = 0.37, 0.52), YNb6Sn6, and ErNb6Sn5 are synthesized from mixtures of the elements (1000-1050°C for 8 d, annealing at 770-850°C for 8-10 d, 30% yield for ErNb6Sn5). The compounds are structurally characterized by single crystal XRD. Sc 2 Nb 3.63 Sn 5 crystallizes in the orthorhombic space group Ibam with Z = 4. Its structure consists of a three-dimensional network composed of two-dimensionally corrugated [Nb2Sn2] and [Nb2Sn3] layers interconnected via Nb-Sn bonds, forming one-dimensional tunnels occupied by Sc atoms. YNb6Sn6 crystallizes in the hexagonal space group P6/mmm with Z = 1 and ErNb6Sn5 in the trigonal space group R3m with Z = 6. Both structures feature three-dimensional networks based on two-dimensional [Nb3Sn], [Sn2], and [LnSn2] (Ln: Y, Er) layers. FPLAPW band structure calculations and magnetic measurements for "Sc 2 Nb 4 Sn 5 " and YNb 6 Sn 6 indicate that both compounds have semimetallic properties and temperature-independent diamagnetic behavior. -(YUE, C.-Y.; LEI*, X.-W.; Inorg. Chem. 51 (2012) 4, 2461-2471, http://dx.