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

• Published in: Frontiers in chemistry Vol. 8; p. 44
• Main Authors: Nagao, Masanori, Miura, Akira, Urushihara, Daisuke, Maruyama, Yuki, Goto, Yosuke, Mizuguchi, Yoshikazu, Moriyoshi, Chikako, Kuroiwa, Yoshihiro, Wang, Yongming, Watauchi, Satoshi, Asaka, Toru, Takano, Yoshihiko, Tadanaga, Kiyoharu, Tanaka, Isao
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 04.02.2020
• Subjects: BiS2 superconductor; Chemistry; flux growth; single crystals; TEM; XAFS
• ISSN: 2296-2646; 2296-2646
• DOI: 10.3389/fchem.2020.00044

Ce 1− x Pr x OBiS 2 (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 Ce 1− x Pr x OBiS 2 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 Ce 0.1 Pr 0.9 OBiS 2 ( 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 Ce 4+ /Ce 3+ . All of the Ce 1− x Pr x OBiS 2 crystals showed superconducting transition, with a maximum transition temperature of ~4 K at x = 0.9.