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arXiv · 1912.11981

Superconductivity in Se-doped La2O2Bi2Pb2S6-xSex with a Bi2Pb2Ch4-type thick conducting layer

Rajveer Jha·Yosuke Goto·Tatsuma D. Matsuda·Yuji Aoki·Yoshikazu Mizuguchi
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Abstract

La2O2Bi2Pb2S6 is a layered Bi-based oxychalcogenide with a thick four-layer-type conducting layer. Although La2O2Bi2Pb2S6 is a structural analogue of La2O2Bi3AgS6, which is a superconductor, insulating behavior has been observed in La2O2Bi2Pb2S6 at low temperatures, and no superconductivity has been reported. Herein, we demonstrate superconductivity in La2O2Bi2Pb2S6-xSex via partial substitution of Se in the S sites. Owing to the Se doping, the normal state electrical resistivity of La2O2Bi2Pb2S6-xSex at low temperatures was dramatically suppressed, and superconductivity was observed at a transition temperature (Tc) of 1.15 K for x = 0.5. Tc increased with increasing Se concentration: Tc = 1.9 K for x = 1.0. The emergence of metallicity and superconductivity was explained via in-plane chemical pressure effects that can suppress local disorder and carrier localization, which are commonly observed in two-layer-type BiS2-based systems.

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Rajveer Jha, Yosuke Goto, Tatsuma D. Matsuda, Yuji Aoki, Yoshikazu Mizuguchi. 2019-12-27. Superconductivity in Se-doped La2O2Bi2Pb2S6-xSex with a Bi2Pb2Ch4-type thick conducting layer. https://doi.org/10.1209/0295-5075/129/67001

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