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arXiv · 1303.6216

Superconductivity induced by electron doping in the system La1-xMxOBiS2 (M = Ti, Zr, Hf, Th)

D. Yazici·K. Huang·B. D. White·I. Jeon·V. W. Burnett·A. J. Friedman·I. K. Lum·M. Nallaiyan·S. Spagna·M. B. Maple
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Abstract

We report a strategy to induce superconductivity in the BiS$_2$-based compound LaOBiS$_2$. Instead of substituting F for O, we increase the charge-carrier density (electron dope) via substitution of tetravalent Th$^{+4}$, Hf$^{+4}$, Zr$^{+4}$, and Ti$^{+4}$ for trivalent La$^{+3}$. It is found that both the LaOBiS$_2$ and ThOBiS$_2$ parent compounds are bad metals and that superconductivity is induced by electron doping with \emph{T$_c$} values of up to 2.85 K. The superconducting and normal states were characterized by electrical resistivity, magnetic susceptibility, and heat capacity measurements. We also demonstrate that reducing the charge-carrier density (hole doping) via substitution of divalent Sr$^{+2}$ for La$^{+3}$ does not induce superconductivity.

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D. Yazici, K. Huang, B. D. White, I. Jeon, V. W. Burnett, A. J. Friedman, I. K. Lum, M. Nallaiyan, S. Spagna, M. B. Maple. 2013-03-25. Superconductivity induced by electron doping in the system La1-xMxOBiS2 (M = Ti, Zr, Hf, Th). https://doi.org/10.1103/physrevb.87.174512

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