Syntheses, crystal and electronic structures, and physical properties of quaternary semiconductors: Ln2Mn3Sb4S12 (Ln = Pr, Nd, Sm, Gd).
Four new quaternary lanthanide antimony sulfides: Ln(2)Mn(3)Sb(4)S(12) (Ln = Pr, Nd, Sm, Gd) have been synthesized from a stoichiometric element mixture at 1373 K by conventional solid state reactions. These compounds crystallize in the monoclinic space group C2/m with the unit cell parameters of a = 19.928(2)-19.9672(6) A, b = 3.9323(4)-3.8803(2) A, c = 14.921(2)-14.9011(1) A, V = 938.5(2)-925.63(6) A(3), and Z = 2 on going from Ln = Pr to Gd. Their structure represents a novel wavy MnS(6) octahedron layer decorated on both sides by chains of an SbS(5) square pyramid via strong Sb-S bonding interactions (< 3.0 A). Such a MnS(6) octahedron layer consists of chains of an edge-sharing [Mn1S(6)](2) dimer extending along [010] that are interconnected by single strings of an edge-sharing Mn2S(6) octahedron at axial S apexes. Sm(2)Mn(3)Sb(4)S(12) displays spin-canted antiferromagnetic interactions between Sm(2+) and Mn(2+) centers and an optical gap of 1.50 eV. The DFT study indicates an indirect band gap with an electronic transfer excitation of S 3p to Sb 5p orbital electrons.
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.
Hua-Jun
HJ
Zhao
Long-Hua
LH
Li
Li-Ming
LM
Wu
Ling
L
Chen