EN
R(O,F)BiS2 (R: La, Ce, Pr, Nd) superconducting
single crystals with different F concentrations are grown
using a CsCl/KCl flux. The obtained 1-2 mm-sized single
crystals have a plate-like shape and are cleavable along
the ab-plane. The crystal structure is tetragonal of space
group P4/nmm (#129). The as-grown single crystals exhibit
superconductivity at around 3–5 K. The superconducting
transition temperature increases with decreasing
the ionic radius of the R element. The superconducting
anisotropies of the R(O,F)BiS2 single crystals are estimated
to be 30–60 according to the effective mass model,
whereas the anisotropies for Ce(O,F)BiS2 single crystals
are 13–21. The c-axis transport measurements of a single
crystal of Pr(O,F)BiS2 under a magnetic field parallel to the
ab-plane reveal a “lock-in” state attributed to the Josephson
vortex flow. Furthermore, the Ce(O,F)BiS2 single crystals
exhibit a magnetic order at the temperature range of
5–7 K that apparently coexist with superconductivity below
approximately 3 K.