Syntheses, Structures, and Electronic Properties of Ba3FeUS6 and Ba3AgUS6

详细信息    查看全文

• 作者：Adel Mesbah ; Christos D. Malliakas ; S茅bastien Leb猫gue ; Amy A. Sarjeant ; Wojciech Stojko ; Lukasz A. Koscielski ; James A. Ibers
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：March 17, 2014
• 年：2014
• 卷：53
• 期：6
• 页码：2899-2903
• 全文大小：440K
• 年卷期：v.53,no.6(March 17, 2014)
• ISSN：1520-510X

文摘

The compounds Ba₃FeUS₆ and Ba₃AgUS₆ have been synthesized by the reactions of BaS, U, S, and M (= Fe or Ag) at 1223 K. These two isostructural compounds crystallize in the K₄CdCl₆ structure type in the trigonal system in space group D_3d⁶鈥?i>R3̅c. Both structures feature infinite _{鈭?/sub>¹[MUS6^{6鈥?/sup>] chains along c that are separated by Ba atoms. The 鈭?/sub>1[FeUS66鈥?/sup>] chains are formed by the face-sharing of US6 trigonal prisms with FeS6 octahedra; in contrast, the 鈭?/sub>1[AgUS66鈥?/sup>] chains are formed by the face-sharing of US6 octahedra with AgS6 trigonal prisms. The Ba3FeUS6 compound charge balances with 3 Ba2+, 1 Fe2+, 1 U4+, and 6 S2鈥?/sup>, whereas Ba3AgUS6 charge balances with 3 Ba2+, 1 Ag1+, 1 U5+, and 6 S2鈥?/sup>. This structure offers a remarkable flexibility in terms of the oxidation state of the incorporated uranium depending on the oxidation state of the d-block metal. DFT calculations performed with the HSE functional have led to band gaps of 2.3 and 2.2 eV for Ba3FeUS6 and Ba3AgUS6, respectively. From resistivity measurements, the Arrhenius activation energies are 0.12(1) and 0.43(1) eV for Ba3FeUS6 and Ba3AgUS6, respectively.}}