Ba1鈥?i>xNaxTi2Sb2O (0.0 鈮?x 鈮?0.33): A Layered Titanium-Based Pnictide Oxide Superconductor

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• 作者：Phuong Doan ; Melissa Gooch ; Zhongjia Tang ; Bernd Lorenz ; Angela M枚ller ; Joshua Tapp ; Paul C. W. Chu ; Arnold M. Guloy
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：October 10, 2012
• 年：2012
• 卷：134
• 期：40
• 页码：16520-16523
• 全文大小：319K
• 年卷期：v.134,no.40(October 10, 2012)
• ISSN：1520-5126

文摘

A new layered Ti-based pnictide oxide superconductor, Ba_1鈥?i>xNa_xTi₂Sb₂O (0.0 鈮?x 鈮?0.33), is reported. X-ray studies revealed that it crystallizes in the tetragonal CeCr₂Si₂C structure. The undoped parent compound, BaTi₂Sb₂O [P4/mmm; a = 4.1196(1) 脜; c = 8.0951(2) 脜], exhibits a charge density wave (CDW)/spin density wave (SDW) transition at 54 K. Upon chemical doping with Na, the CDW/SDW transition is systematically suppressed, and superconductivity arises with the critical temperature (T_c) increasing to 5.5 K. Bulk superconductivity was confirmed by resistivity, magnetic, and heat capacity measurements. Like the high-T_c cuprates and the iron pnictides, the superconductivity in BaTi₂Sb₂O arises from an ordered state. Similarities and differences between BaTi₂Sb₂O and the cuprate and iron pnictide superconductors are discussed.