Crystal structure, chemical bonding and magnetic properties of the new antimonides Ce2Ir3Sb4, La2Ir3Sb4, and Ce2Rh3Sb4

Abstract

Abstract The antimonides Ce2Ir3Sb4, La2Ir3Sb4, and Ce2Rh3Sb4 were synthesized by solid state reaction from the elements. The crystal structures of these compounds were determined from single crystal X-ray diffraction data. Ce2Ir3Sb4 crystallises in a new structure type in the space group Pnma (no. 62) with a = 16.1510(8) Å, b = 4.5600(3) Å, c = 10.9463(5) Å. La2Ir3Sb4 and Ce2Rh3Sb4 crystallise in the Ce2Ir3Sb4 structure type as well with a = 16.2659(10) Å, b = 4.5896(3) Å, c = 10.9996(7) Å) and a = 16.2293(8) Å, b = 4.5604(2) Å, c = 10.9804(5) Å, respectively. The four- and five-bonded transition metal atoms and three- and four-bounded Sb atoms form a 3D-network with the rare-earth metal embedded in its cavities, resembling the topology of Ca in the CaBe2Ge2 or Th in ThCr2Si2 type. Magnetic susceptibility and X-ray absorption near edge spectroscopy data indicate a stable trivalent state for Ce in the Ce2Ir3Sb4 compound.