TY - JOUR
T1 - Syntheses, crystal structures, transport properties, and theoretical studies of five members of the MAn2Q5 Family
T2 - SrU2S5, BaU2Se5, PbU2S5, BaTh2S5, and BaU2Te5
AU - Prakash, Jai
AU - Tarasenko, Mariya S.
AU - Mesbah, Adel
AU - Lebègue, Sébastien
AU - Malliakas, Christos D
AU - Ibers, James A
PY - 2014/11/3
Y1 - 2014/11/3
N2 - 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.
AB - 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.
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U2 - 10.1021/ic501795w
DO - 10.1021/ic501795w
M3 - Article
C2 - 25302522
AN - SCOPUS:84908618224
VL - 53
SP - 11626
EP - 11632
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 21
ER -