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arXiv · 1709.00892

Superconductivity in La1-xCexOBiSSe: carrier doping by mixed valence of Ce ions

Ryota Sogabe·Yosuke Goto·A. Nishida·Takayoshi Katase·Yoshikazu Mizuguchi
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Abstract

We report the effects of Ce substitution on structural, electronic, and magnetic properties of layered bismuth-chalcogenide La1-xCexOBiSSe (x = 0-0.9), which are newly obtained in this study. Metallic conductivity was observed for x > 0.1 because of electron carriers induced by mixed valence of Ce ions, as revealed by bond valence sum calculation and magnetization measurements. Zero resistivity and clear diamagnetic susceptibility were obtained for x = 0.2-0.6, indicating the emergence of bulk superconductivity in these compounds. Dome-shaped superconductivity phase diagram with the highest transition temperature (Tc) of 3.1 K, which is slightly lower than that of F-doped LaOBiSSe (Tc = 3.7 K), was established. The present study clearly shows that the mixed valence of Ce ions can be utilized as an alternative approach for electron-doping in layered bismuth-chalcogenides to induce superconductivity.

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Ryota Sogabe, Yosuke Goto, A. Nishida, Takayoshi Katase, Yoshikazu Mizuguchi. 2017-09-04. Superconductivity in La1-xCexOBiSSe: carrier doping by mixed valence of Ce ions. https://doi.org/10.1209/0295-5075/122/17004

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