Syntheses, crystal and electronic structures, and physical properties of two quaternary chalcogenides: La(4)FeSb(2)Q(10) (Q = S, Se).
Two new quaternary chalcogenides, La(4)FeSb(2)S(10) and La(4)FeSb(2)Se(10), have been synthesized from the stoichiometric mixture of elements by solid-state reactions at 1100 degrees C. The compounds crystallize in the orthorhombic space group Pbcm with a = 15.066(4) A, b = 7.590(2) A, c = 13.341(4) A, and Z = 4 and a = 15.596(5) A, b = 7.869(2) A, c = 13.960(4) A, and Z = 4, respectively. These structures represent an unique three-dimensional network, in which SbQ(3) trigonal pyramids (Sb-S < 2.60 A, Sb-Se < 2.80 A) are connected via a relatively weak Sb-Q bond (Sb-S approximately 2.90 A, Sb-Se approximately 3.00 A) in a novel teeter-totter (SbQ(4))(n) chain motif. The theoretical studies confirm the Sb-Q bonding interactions within such teeter-totter chains. Their optical band gaps are measured to be 1.00 and 0.85 eV. At room temperature, their electrical conductivities are about 10(-4) S/cm. Both compounds display antiferromagnetic interactions between Fe centers, and their effective magnetic moments are 5.25 and 6.17 micro(B), respectively.
Zhao
Hua-Jun
HJ
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.
Li
Long-Hua
LH
Wu
Li-Ming
LM
Chen
Ling
L