EuIrIn₄ with LaCoAl₄ Type Structure – Synthesis, Magnetic Properties, and ¹⁵¹Eu Mössbauer Spectroscopy

LaCoAl 4 type EuIrIn 4 was synthesized by induction‐melting of the elements in a sealed tantalum ampoule, followed by annealing of the sample in a high‐frequency or in a muffle furnace. The EuIrIn 4 structure was refined from single‐crystal X‐ray diffraction data: Pmma, a = 860.65(3), b = 430.33(6), c = 757.65(7) pm, wR = 0.0748, 633 F 2 values and 24 variables. The striking building units are iridium‐centered trigonal prisms of indium atoms, distorted bcc indium cubes and a pentagonal prismatic indium coordination of the europium atoms. Within the three‐dimensional [IrIn 4 ] 2– polyanionic network the Ir–In and In–In distances range from 260–288 pm and 306–332 pm, respectively. The divalent ground state of europium was manifested through magnetic [7.96(1) μ B / Eu atom, T N = 7.9(1) K] and 151 Eu Mössbauer spectroscopic data [ δ = –10.54(2) mm · s –1 ; B hf = 19.1(1) T at 6 K].