EuIrIn4 with LaCoAl4 Type Structure - Synthesis, Magnetic Properties, and 151Eu Mossbauer 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, 633F(2)values and 24 variables. The striking building units are iridium-centered trigonal prisms of indium atoms, distortedbccindium cubes and a pentagonal prismatic indium coordination of the europium atoms. Within the three-dimensional [IrIn4](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) mu(B)/ Eu atom,T-N= 7.9(1) K] and(151)Eu Mossbauer spectroscopic data [delta= -10.54(2) mm center dot s(-1); B-hf= 19.1(1) T at 6 K].