Superconductivity in BiS2 based Bi4O4S3 novel compound

We report here synthesis and basic characterizations of Bi4O4S3 superconductor. The sample is crystallized in tetragonal I4/mmm space group with lattice parameters a = 3.969(2) angstrom, c = 41.352(1) angstrom. Both DC magnetization and resistivity measurements confirmed that Bi4O4S3 is a bulk superconductor with superconducting transition temperature (T-c) of 4.4K. Closed loops in isothermal magnetization (MH) measurements are clear signature of flux pinning and irreversible behavior. The lower critical field (H-c1) is found to be similar to 15 Oe at 2K. The magneto- transport P(T, H) measurements showed resistive broadening and decrease in Tc (P = 0) with increasing magnetic field. Upper critical field calculated through extrapolation H-c2(0) is similar to 31kOe with corresponding Ginzburg-Landau coherence length similar to 100 angstrom. Our magnetization and electrical transport measurements substantiate the appearance of bulk superconductivity in as synthesized Bi4O4S3