Syntheses, crystal structures, transport properties, and theoretical studies of five members of the MAn2Q5 Family: SrU2S5, BaU2Se5, PbU2S5, BaTh2S5, and BaU2Te5

Jai Prakash, Mariya S. Tarasenko, Adel Mesbah, Sébastien Lebègue, Christos D Malliakas, James A Ibers*

*Corresponding author for this work

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14 Scopus citations

Abstract

Five compounds of the MAn2Q5 family, namely, SrU2S5, BaU2Se5, PbU2S5, BaTh2S5, and BaU2Te5, have been synthesized by higherature solid-state reactions. The crystal structures of these compounds were determined by single-crystal X-ray diffraction studies. SrU2S5, BaU2Se5, PbU2S5, and BaTh2S5 crystallize in the PbU2Se5 structure type in space group C2h5-P21/c of the monoclinic system, whereas BaU2Te5 adopts the (NH4)Pb2Br5 structure type in space group D4h18-I4/mcm of the tetragonal system. There are no Q-Q bonds in these structures, so the formulas charge balance as M2+(An4+)2(Q2-)5. The An atoms in the monoclinic structure are seven- or eight-coordinated by Q atoms; the U atoms in the tetragonal structure are eight-coordinated. The M atoms in the monoclinic structure are coordinated to either eight or nine Q atoms, depending on the monoclinic angle; the M atoms in the tetragonal structure are 10-coordinated. Resistivity studies on single crystals of SrU2S5, BaU2Se5, and PbU2S5 show metallic behavior with resistivities of 0.24, 10, and 3.3 m·cm, respectively, at 298 K. Spin-polarized density functional theory in the generalized gradient approximation applied to the four U compounds suggests that they are ferromagnetic. In each compound, the density of states of one spin channel is found to be finite at the Fermi level, whereas there is a gap in the density of states of the other spin channel; this is characteristic of a half-metal.

Original languageEnglish (US)
Pages (from-to)11626-11632
Number of pages7
JournalInorganic chemistry
Volume53
Issue number21
DOIs
Publication statusPublished - Nov 3 2014

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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