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

paper

Tetragonality induced superconductivity in anti-ThCr $_{2}$ Si $_{2}$ -type $R E_{2}$ O $_{2}$ Bi ( $R E$ = rare earth) with Bi square net

arXiv:2003.05598 · doi:10.1039/C9DT04640B

Abstract

We report a series of layered superconductors, anti-ThCr $_{2}$ Si $_{2}$ -type $R E_{2}$ O $_{2}$ Bi ( $R E$ = rare earth), composed of electrically conductive Bi square nets and magnetic insulating $R E_{2}$ 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 $R E_{2}$ O $_{2}$ layers. Intriguingly, the transition temperature of all $R E_{2}$ 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.

Tetragonality induced superconductivity in anti-ThCr2​Si2​-type RE2​O2​Bi (RE = rare earth) with Bi square net

Abstract

Tetragonality induced superconductivity in anti-ThCr $_{2}$ Si $_{2}$ -type $R E_{2}$ O $_{2}$ Bi ( $R E$ = rare earth) with Bi square net