Structural, Optical, and Magnetic Properties of Na₈Eu₂(Si₂S₆)₂ and Na₈Eu₂(Ge₂S₆)₂: Europium(II) Quaternary Chalcogenides That Contain an Ethane-like (Si₂S₆)⁶ˉ or (Ge₂S₆)⁶ˉ Moiety
Abstract
Two isostructural europium(II) quaternary chalcogenides, Na8Eu2(Si2S6)2, 1, and Na8Eu2(Ge2S6)2, 2, containing an ethane-like (Si2S6)6- or (Ge2S6)6- moiety have been synthesized by employing the polychalcogenide molten flux method. Single-crystal X-ray diffraction reveals that both compounds crystallize in the C2/m space group, and their structures contain layers of {[Na2Eu2(Si2S6)2]6-}∞ or {[Na2Eu2(Ge2S6)2]6-}∞ anions held together by six interlayer sodium cations to yield {Na6[Na2Eu2(Si2S6)2]}∞ and {Na6[Na2Eu2(Ge2S6)2]}∞. Compound 2 is a semiconductor with an optical band gap of 2.15(2) eV. The temperature dependence of the magnetic susceptibility indicates that compounds 1 and 2 are paramagnetic with eff=7.794(1) B per Eu and g=1.964(1) for 1 and eff=8.016(1) B per Eu and g=2.020(1) for 2, moments that are in good agreement with the europium(II) spin-only moment of 7.94 B. The europium-151 Mössbauer isomer shift of 2 confirms the presence of europium(II) cations with an electronic configuration between [Xe]4f6.81 and 4f76s0.32.
Recommended Citation
A. Choudhury et al., "Structural, Optical, and Magnetic Properties of Na₈Eu₂(Si₂S₆)₂ and Na₈Eu₂(Ge₂S₆)₂: Europium(II) Quaternary Chalcogenides That Contain an Ethane-like (Si₂S₆)⁶ˉ or (Ge₂S₆)⁶ˉ Moiety," Journal of Solid State Chemistry, vol. 226, pp. 74 - 80, Academic Press Inc., Mar 2015.
The definitive version is available at https://doi.org/10.1016/j.jssc.2015.02.006
Department(s)
Chemistry
Sponsor(s)
National Science Foundation (U.S.)
Fonds National de la Recherche Scientifique, Belgium
Keywords and Phrases
Chalcogenides; Energy Gap; Ethane; Europium; Germanium; Inorganic Compounds; Magnetic Properties; Magnetic Susceptibility; Positive Ions; Semiconductor Materials; Silicon; Silicon Wafers; Single Crystals; Sodium Compounds; Temperature Distribution; X Ray Diffraction; Electronic Configuration; Isomer Shifts; Isostructural; Quaternary Chalcogenides; Single Crystal X-ray Diffraction; Sodium Cations; Ssbauer Spectroscopies; Temperature Dependence; Europium Compounds
International Standard Serial Number (ISSN)
0022-4596
Electronic OCLC #
36946153
Print OCLC #
1783527
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2015 Academic Press Inc., All rights reserved.
Publication Date
01 Mar 2015
Comments
Financial support by National Science Foundation (U.S.), Grant No. NSF-DMR-0343412; and the Fonds National de la Recherche Scientifique, Belgium, Grants Nos. 9.456595 and 1.5.064.05.