Ba1-xNaxTi2Sb2O (0.0 <= x <= 0.33): A Layered Titanium-based Pnictide Oxide Superconductor

Abstract

A new layered Ti-based pnictide oxide superconductor, Ba1-xNaxTi2Sb2O (0.0 <= x <= 0.33), is reported. X-ray studies reveal it crystallizes in the tetragonal CeCr2Si2C structure. The undoped parent compound, BaTi2Sb2O (P4/mmm; a=4.1196(1)Å; c=8.0951(2)Å), exhibits a CDW/SDW transition at 54K. Upon chemical doping with Na, the CDW/SDW transition is systematically suppressed and super-conductivity arises with the critical temperatures, Tc, increasing to 5.5 K. Bulk superconductivity is confirmed by resistivity, magnetic and heat capacity measurements. Like the high-Tc cuprates and the iron pnictides, superconductivity in BaTi2Sb2O arises from an ordered state. Similarities and differences to the cuprate and iron pnictide supercon-ductors are discussed.

4 pages, 7 figures, + supporting information

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Cited by in corpus (5)

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• Superconductivity, charge- or spin-density wave, and metal-nonmetal transition in BaTi${}_2$(Sb${}_{1-x}$Bi${}_x$)${}_2$O
• Electron-phonon superconductivity and charge density wave instability in the layered titanium-based pnictide BaTi${}_2$Sb${}_2$O
• Formation of the density wave energy gap in Na${}_2$Ti${}_2$Sb${}_2$O: an optical spectroscopy study