Ce13Ir34.4P24 – An intergrowth structure of ThCr2Si2, SrPtSb, and CeMg2Si2 related slabs

Abstract

Abstract Well-shaped needles of the metal-rich phosphide Ce13Ir34.4P24 were synthesized by a reaction of the elements in a lead flux (1 : 2 : 2 : 60 molar ratio, 1370 K, slow cooling rate of 2 K/h). Ce13Ir34.4P24 was characterized by X-ray powder and single crystal data: new structure type C2/m (mS144–1.2), a = 4512.2(9), b = 398.51(8), c = 1331.1(2) pm, β = 105.01(2)°, wR2 = 0.0326, 3554 F 2 values and 186 variables. The structure is built up from a complex three-dimensional [Ir34.4P24] δ– polyanion in which the seven crystallographically independent cerium atoms fill distorted hexagonal cavities. Geometrically the Ce13Ir34.4P24 structure can be described as an intergrowth variant of ThCr2Si2, SrPtSb, and CeMg2Si2 related slabs, similar to Lu3Ir7P5, Sm15Ir33P26, and Ce4Ir14P9.