In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 69, No. 11-12 ( 2014-12-1), p. 1097-1104
Abstract:
The lanthanum-rich antimonide La 2 NiSb was synthesized by annealing a cold-pressed pellet of the elements in a sealed silica glas tube at 1120 K. La 2 NiSb was characterized by powder and single-crystal X-ray diffraction: ordered Bi 3 Ni type, Pnma, Z =4, a=825.6(3), b=452.2(2), c=1195.5(4) pm, wR=0.0695, 856 F 2 values, 26 variables. The nickel atoms form infinite zigzag chains (259 pm Ni-Ni) with trigonal-prismatic lanthanum coordination for each nickel atom. The antimony atoms cap the rectangular faces of the lanthanum prisms (336 pm La-Sb) and thereby coordinate also the nickel atoms (271 pm Ni-Sb). These rods run parallel to the b axis and form a herringbone pattern, similar to the FeB-type structure of GdNi. Although metallic conductivity is expected for La 2 NiSb from DFT-based band structure calculations, the real-space bonding analysis shows prominent localization of electrons on antimonide anions and positively charged lanthanum cations. The chain substructure is strongly bonded by polar covalent Ni-Sb and multicenter Ni-Ni interactions. The nickel atoms, which are involved in multicenter bonding with adjacent nickel and lanthanum atoms, provide a conductivity pathway along the prismatic strands. 121 Sb Mössbauer spectroscopic data at 78 K show a single signal at an isomer shift of -7.62(3)mms -1 , supporting the antimonide character. La 2 NiSb shows weak paramagnetism with a susceptibility of 2.5 x 10 -3 emu mol -1 at room temperature.
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.5560/znb.2014-4135
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2014
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
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