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Title: Syntheses, crystal structures, and properties of EuRhIn, EuIr{sub 2}, and EuIrSn{sub 2}

Journal Article · · Journal of Solid State Chemistry

The title compounds were prepared from the elements by reactions in sealed tantalum tubes in a high-frequency furnace. Their structures were refined from single crystal X-ray diffractometer data: Pnma, a = 744.4(1) pm, b = 434.15(9) pm, c = 845.5(1) pm, wR2 = 0.0433, 658 F{sup 2} values, 20 variables for EuRhIn, Rd3m, a = 756.5(1) pm, wR2 = 0.0349, 94 F{sup 2} values, 5 variables for EuIr{sub 2}, and Cmcm, a = 434.78(3) pm, b = 1124.0(1) pm, c = 751.20(5) pm, wR2 = 0.0561, 565 F{sup 2} values, 16 variables for EuIrSn{sub 2}. EuRhIn crystallizes with a TiNiSi type structure that consists of strongly puckered Rh{sub 3}In{sub 3} hexagons. The europium atoms fill the channels within the three-dimensional [RhIn] polyanion. EuRhIn orders ferromagnetically at 22.0(5) K with a saturation magnetic moment of 6.7(1) {mu}{sub B}/Eu at 4 k and 5.5 T. The divalent character of the europium atoms in EuRhIn was determined from temperature dependent susceptibility (7.9 {mu}{sub B}/Eu in the high-temperature part) and {sup 151}Eu Moessbauer spectroscopic experiments. The latter show an isomer shift of {delta} = {minus}8.30(2) mm/s at 78 K. At 4.2 K full magnetic hyperfine field splitting subjected to significant quadrupole splitting of {Delta}E{sub Q} = 8 mm/s is observed. EuRhIn is a metallic conductor with a room temperature value of 58 {micro}{Omega}cm for the specific resistivity. The structure of the Laves phase EuIr{sub 2} is confirmed on the basis of single crystal X-ray data. The iridium atoms form a tetrahedral network with Ir-Ir distances of 268 pm. EuIrSn{sub 2} adopts a MgCuAl{sub 2} type structure that may be described as an iridium-filled variant of a distorted CaIn{sub 2}-like sublattice of composition EuSn{sub 2}. The tin atoms in the distorted and puckered hexagonal network have shorter (303 and 322 pm) and longer (343 pm) tin-tin contacts. 40 refs., 9 figs., 5 tabs.

OSTI ID:
679227
Journal Information:
Journal of Solid State Chemistry, Vol. 145, Issue 1; Other Information: PBD: Jun 1999
Country of Publication:
United States
Language:
English