Ternary Rare-Earth Titanium Antimonides RE2Ti11 − xSb14 + x (RE = Sm, Gd, Tb, Yb)

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• 作者：Haiying Bie ; Arthur Mar
• 刊名：Inorganic Chemistry
• 出版年：2008
• 出版时间：August 4, 2008
• 年：2008
• 卷：47
• 期：15
• 页码：6763-6770
• 全文大小：456K
• 年卷期：v.47,no.15(August 4, 2008)
• ISSN：1520-510X

文摘

The isostructural rare-earth titanium antimonides RE₂Ti_11 − xSb_14 + x (RE = Sm, Gd, Tb, Yb) have been synthesized by arc-melting reactions of the elements. Single-crystal X-ray diffraction revealed that they adopt a new structure type (Pearson symbol oP54, space group Pnma, Z = 2; a = 15.8865(6)−15.9529(9) Å, b = 5.7164(2)−5.7135(3) Å, c = 12.9244(5)−12.9442(7) Å for RE = Sm−Yb). The structure consists of titanium-centered octahedra (CN6) and pentagonal bipyramids (CN7) connected to form a 3D framework whose cavities are filled with RE atoms. 1D linear skewers of titanium atoms, within face-sharing octahedral chains, and similar skewers of antimony atoms, associated with the titanium-centered pentagonal bipyramids, extend along the b direction. On proceeding from Sm₂Ti₁₁Sb₁₄ to Tb₂Ti_10.41(1)Sb_14.59(1) and Yb₂Ti_10.58(1)Sb_14.42(1), antimony atoms are disordered within some of the titanium sites. Resistivity measurements on the samarium and ytterbium members indicated metallic behavior.