Tetragonality induced superconductivity in anti-ThCr$_2$Si$_2$-type $RE_2$O$_2$Bi ($RE$ = rare earth) with Bi square net

Ryosuke Sei; Hideyuki Kawasoko; Kota Matsumoto; Masato Arimitsu; Kyohei Terakado; Daichi Oka; Shintaro Fukuda; Noriaki Kimura; Hidetaka Kasai; Eiji Nishibori; Kenji Ohoyama; Akinori Hoshikawa; Toru Ishigaki; Tetsuya Hasegawa; Tomoteru Fukumura

doi:10.1039/c9dt04640b

arXiv · 2003.05598

Tetragonality induced superconductivity in anti-ThCr$_2$Si$_2$-type $RE_2$O$_2$Bi ($RE$ = rare earth) with Bi square net

Ryosuke Sei·Hideyuki Kawasoko·Kota Matsumoto·Masato Arimitsu·Kyohei Terakado·Daichi Oka·Shintaro Fukuda·Noriaki Kimura·Hidetaka Kasai·Eiji Nishibori·Kenji Ohoyama·Akinori Hoshikawa·Toru Ishigaki·Tetsuya Hasegawa·Tomoteru Fukumura

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Abstract

We report a series of layered superconductors, anti-ThCr$_2$Si$_2$-type $RE_2$O$_2$Bi ($RE$ = rare earth), composed of electrically conductive Bi square nets and magnetic insulating $RE_2$O$_2$ layers. The superconductivity was induced by separating Bi square nets as a result of excess oxygen incorporation, irrespective of the presence of magnetic ordering in $RE_2$O$_2$ layers. Intriguingly, the transition temperature of all $RE_2$O$_2$Bi including nonmagnetic Y$_2$O$_2$Bi was approximately scaled by the unit cell tetragonality ($c$/$a$), implying a key role of relative separation of the Bi square nets to induce the superconductivity.

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Ryosuke Sei, Hideyuki Kawasoko, Kota Matsumoto, Masato Arimitsu, Kyohei Terakado, Daichi Oka, Shintaro Fukuda, Noriaki Kimura, Hidetaka Kasai, Eiji Nishibori, Kenji Ohoyama, Akinori Hoshikawa, Toru Ishigaki, Tetsuya Hasegawa, Tomoteru Fukumura. 2020-03-12. Tetragonality induced superconductivity in anti-ThCr$_2$Si$_2$-type $RE_2$O$_2$Bi ($RE$ = rare earth) with Bi square net. https://doi.org/10.1039/c9dt04640b

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