Eu₁₀Mn₆Sb₁₃: A New Ternary Rare-earth Transition-metal Zintl Phase
A new transition-metal-containing Zintl compound, Eu10Mn6Sb13, was prepared by a high-temperature Sn-flux synthesis. The structure was determined by single-crystal X-ray diffraction. Eu10Mn6Sb13 crystallizes in the monoclinic space group C2/m with a = 15.1791(6) Å, b = 19.1919(7) Å, c = 12.2679(4) Å, β = 108.078(1)°, Z = 4 (R1 = 0.0410, wR2 = 0.0920), and T = 90(2) K. The structure of Eu10Mn16Sb13 is composed of double layers of Mn-centered tetrahedra separated by Eu2+ cations. The double layers are composed of edge- and corner-sharing Mn-centered tetrahedra which form cavities occupied by Eu2+ cations and [Sb2]4- dumbbells. Linear [Sb3]5- trimers bridging two tetrahedra across the cavity are also present. Bulk susceptibility data indicate paramagnetic behavior with a ferromagnetic component present below 60 K. Temperature-dependent electrical resistivity measurements show semiconducting behavior above 60 K (Ea = 0.115(2) eV), a large and unusually sharp maximum in the resistivity at ∼40 K, and metallic behavior below 40 K. 151Eu Mössbauer spectra confirm that the europium is divalent with an average isomer shift of -11.2(1) mm/s at 100 K; the spectra obtained below 40 K reveal magnetic ordering of six of the seven europium sublattices and, at 4.2 K, complete ordering of the seven europium sublattices.
A. P. Holm and S. M. Park and C. L. Condron and M. M. Olmstead and H. Kim and P. Klavins and F. Grandjean and R. P. Hermann and G. J. Long and M. G. Kanatzidis and S. M. Kauzlarich and S. J. Kim, "Eu₁₀Mn₆Sb₁₃: A New Ternary Rare-earth Transition-metal Zintl Phase," Inorganic Chemistry, American Chemical Society (ACS), Jan 2003.
The definitive version is available at http://dx.doi.org/10.1021/ic034054w
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