Structure, Superconductivity, and Magnetism of Ce(O,F)BiS₂ Single Crystals

The crystal structures of Ce­(O,F)­BiS2 synthesized from starting materials with five different F contents were determined by single-crystal X-ray analysis. An increase in F content in the starting materials slightly increased F incorporation in the grown single crystals. The grown crystals with various F contents showed similar layered structures, but minor structural changes were observed with different conductive and magnetic properties. Crystals grown from higher F content were found to have a nearly flat Bi–S plane and elongated Ce–(O,F) bond, and showed superconductive transition below ∼3 K and spontaneous magnetization below ∼7 K. The calculated density of states based on this structural analysis predicted that hybridized Bi 6p–S 3p orbitals intersect the Fermi level and that Ce states are located near the Fermi level. The effect of structural change on superconductivity and long-range magnetic ordering has been discussed.