F-substituted LaOBiSe2 single crystals were grown using CsCl flux. The obtained single crystals showed a plate-like shape with a size of about 1.0 mm square. The c-axis lattice constant of the grown crystals was determined to be 14.114(3) {AA}. The s
uperconducting critical temperature of the single crystal was approximately 3.5 K. The superconducting anisotropies were determined to be 49 and 24 using the upper critical field and the effective mass model, respectively.
F-substituted ROBiS2 (R = La, Ce, Nd) superconducting single crystals with different F concentration were grown successfully using CsCl/KCl flux. All the obtained single crystals had a plate-like shape with a well-developed ab-plane of 1-2 mm in size
. The flux components of Cs, K, and Cl were not detected in the obtained single crystals by electron probe microanalysis. The grown single crystals of F-substituted LaOBiS2 and CeOBiS2 showed superconducting at about 3 K while the Tc of the F-substituted NdOBiS2 exhibited approximately 5 K. The superconducting anisotropy of the single crystals of F-substituted LaOBiS2 and NdOBiS2 was estimated to be 30-45 according to the effective mass model whereas those values were 13-21 for the F-substituted CeOBiS2 single crystals. The F-substituted CeOBiS2 single crystals exhibited magnetic order at about 7 K that apparently coexisted with superconductivity below around 3 K.
F-substituted NdOBiS2 superconducting single crystals were grown using CsCl/KCl flux. This is the first example of the single-crystal growth of a BiS2-based superconductor. The obtained single crystals had a plate-like shape with a size of 1-2 mm and
a well-developed ab-plane. The crystal structure of the grown crystals was determined by single-crystal X-ray diffraction analysis to be the tetragonal space group P4/nmm (#129) with a = 3.996(3) A and c = 13.464(6) A. The chemical formula of the grown crystals was approximately Nd0.98(0.06)O0.7(0.1)F0.3(0.1)Bi0.98(0.04)S2, and Cs, K, and Cl were not detected in the grown crystals by electron probe microanalysis. The grown crystals had a critical temperature of approximately 5 K. The superconducting anisotropy of the single crystals was estimated to be about 30 from the effective mass model and the upper critical field.
