AUTHOR=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 

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

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00044

DOI=10.3389/fchem.2020.00044

ISSN=2296-2646

ABSTRACT=<p>Ce<sub>1−<italic>x</italic></sub>Pr<sub><italic>x</italic></sub>OBiS<sub>2</sub> (0. 1 ≤ <italic>x</italic> ≤ 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<sub>1−<italic>x</italic></sub>Pr<sub><italic>x</italic></sub>OBiS<sub>2</sub> single crystals with 0.1 ≤ <italic>x</italic> ≤ 0.9 exhibited tetragonal phase. With increasing Pr content, the <italic>a</italic>-axis and <italic>c</italic>-axis lattice parameters decreased and increased, respectively. Transmission electron microscope analysis of Ce<sub>0.1</sub>Pr<sub>0.9</sub>OBiS<sub>2</sub> (<italic>x</italic> = 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<sup>4+</sup>/Ce<sup>3+</sup>. All of the Ce<sub>1−<italic>x</italic></sub>Pr<sub><italic>x</italic></sub>OBiS<sub>2</sub> crystals showed superconducting transition, with a maximum transition temperature of ~4 K at <italic>x</italic> = 0.9.</p>