Crystal Structure and Superconductivity of Tetragonal and Monoclinic Ce1- xPr xOBiS2

Akira Miura; Masanori Nagao; Yosuke Goto; Yoshikazu Mizuguchi; Tatsuma D Matsuda; Yuji Aoki; Chikako Moriyoshi; Yoshihiro Kuroiwa; Yoshihiko Takano; Satoshi Watauchi; Isao Tanaka; Nataly Carolina Rosero-Navarro; Kiyoharu Tadanaga

doi:10.1021/acs.inorgchem.8b00349

Crystal Structure and Superconductivity of Tetragonal and Monoclinic Ce_{1- x}Pr _xOBiS₂

Inorg Chem. 2018 May 7;57(9):5364-5370. doi: 10.1021/acs.inorgchem.8b00349. Epub 2018 Apr 20.

Affiliations

¹ Faculty of Engineering , Hokkaido University , Kita 13, Nishi 8 , Sapporo 060-8628 , Japan.
² Center for Crystal Science and Technology , University of Yamanashi , 7-32 Miyamae , Kofu 400-8511 , Japan.
³ Department of Physics , Tokyo Metropolitan University , 1-1 minami-osawa , Hachioji, Tokyo 192-0397 , Japan.
⁴ Department of Physical Science , Hiroshima University , 1-3-1 Kagamiyama , Higashihiroshima, Hiroshima 739-8526 Japan.
⁵ MANA , National Institute for Materials Science , 1-2-1 Sengen , Tsukuba 305-0047 , Japan.

PMID: 29676897
DOI: 10.1021/acs.inorgchem.8b00349

Abstract

Ce_{1- x}Pr _xOBiS₂ powders and Ce_0.5Pr_0.5OBiS₂ single crystals were synthesized and their structure and superconductive properties were examined by X-ray diffraction, X-ray absorption, electronic resistivity, and magnetization. While PrOBiS₂ was found to be in a monoclinic phase with one-dimensional Bi-S zigzag chains showing no superconductive transition above 0.1 K, CeOBiS₂ was in a tetragonal phase with two-dimensional Bi-S planes showing zero resistivity below 1.3 K. In the range x = 0.3-0.9 in Ce_{1- x}Pr _xOBiS₂, both monoclinic and tetragonal phases were formed together with zero resistivity up to a maximum temperature of 2.2 K. A Ce_0.5Pr_0.5OBiS₂ single crystal, which showed both zero resistivity and a decrease in magnetization at ∼2.4 K, presented a tetragonal structure. Short Bi-S bonding in flat two-dimensional Bi-S planes and mixed Ce³⁺/Ce⁴⁺ were characteristic features of the Ce_0.5Pr_0.5OBiS₂ single crystal, which presumably triggered its superconductivity.