Upper critical field of the single crystal La(O,F)BiSe₂

Single crystal growth and superconducting properties of LaO_0.5F_0.5BiSe₂ are studied. Single crystals of LaO_0.5F_0.5BiSe₂ were grown by a CsCl-flux method. Electrical resistivity ρ(T) measurements were performed to elucidate its superconducting properties. The ρ(T) shows metallic behavior and superconducting transition at 4.0 K. From ρ(T) measurements in several magnetic fields, upper critical fields $H_{c2}^{\parallel ab}$(0) and $H_{c2}^{\parallel c}$(0) are estimated to be 7.05 T and 0.52 T, respectively. The superconducting anisotropic parameter Γ is determined to be 13.6. (paper)