Superconductivity at 5K in NdO0.5F0.5BiS2

We report appearance of superconductivity at 5K in NdO0.5F0.5BiS2 and supplement the discovery [Demura et al., e-print arXiv:1207.5248] of the same in layered sulfide based compound. Detailed structural analysis showed that the studied compound is crystallized in tetragonal P4/nmm space group with lattice parameters a = 3.9911(3) angstrom and c = 13.3830(2) angstrom. Bulk superconductivity is established in NdO0.5F0.5BiS2 at 5K by both transport and magnetic measurements. Electrical transport measurements showed superconducting T-c onset at 5.2K and T-c (rho = 0) at 4.7K. Under applied magnetic field, both T-c onset and T-c (rho = 0) decrease to lower temperatures and an upper critical field [H-c2(0)] of above 23 kOe is estimated. Isothermal magnetization exhibited typical type-II behavior with lower critical field (H-c1) of around 25 Oe. Specific heat [C-p(T)] is investigated in the temperature range of 1.9-50K in zero external magnetic field. A Schottky-type anomaly is observed at low temperature below 7K