Frontiers in Chemistry (Feb 2020)

Flux Growth and Superconducting Properties of (Ce,Pr)OBiS2 Single Crystals

  • Masanori Nagao,
  • Akira Miura,
  • Daisuke Urushihara,
  • Yuki Maruyama,
  • Yosuke Goto,
  • Yoshikazu Mizuguchi,
  • Chikako Moriyoshi,
  • Yoshihiro Kuroiwa,
  • Yongming Wang,
  • Satoshi Watauchi,
  • Toru Asaka,
  • Yoshihiko Takano,
  • Kiyoharu Tadanaga,
  • Isao Tanaka

DOI
https://doi.org/10.3389/fchem.2020.00044
Journal volume & issue
Vol. 8

Abstract

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Ce1−xPrxOBiS2 (0. 1 ≤ x ≤ 0.9) single crystals were grown using a CsCl flux method. Their structural and physical properties were examined by X-ray diffraction, X-ray absorption, transmission electron microscopy, and electrical resistivity. All of the Ce1−xPrxOBiS2 single crystals with 0.1 ≤ x ≤ 0.9 exhibited tetragonal phase. With increasing Pr content, the a-axis and c-axis lattice parameters decreased and increased, respectively. Transmission electron microscope analysis of Ce0.1Pr0.9OBiS2 (x = 0.9) single crystal showed no stacking faults. Atomic-resolution energy dispersive X-ray spectrometry mapping revealed that Bi, Ce/Pr, O, and S occupied different crystallographic sites, while Ce and Pr randomly occupied the same sites. X-ray absorption spectra showed that an increase of the Pr ratio increased the ratio of Ce4+/Ce3+. All of the Ce1−xPrxOBiS2 crystals showed superconducting transition, with a maximum transition temperature of ~4 K at x = 0.9.

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