Superconducting properties of BiS2-based superconductor NdO1−xFxBiS2 (x = 0 to 0.9)
We report the phase diagram of NdO1−x F x BiS2 (x = 0.1, 0.3, 0.5, 0.7, 0.9) compound. The samples synthesized by the vacuum encapsulation technique are crystallized in a tetragonal P4/nmm space group. The superconductivity of all samples is confirmed by dc magnetic susceptibility and electrical transport measurements. The highest superconducting transition temperature (T c) onset of 5.25 K is seen for the NdO0.3F0.7BiS2 sample. Superconductivity is suppressed with an applied magnetic field, as both T c onset and T c (ρ = 0) are decreased to lower temperatures in magneto transport ρ(T, H) measurements. The upper critical field H c2(0) is estimated to be above 3Tesla for NdO0.3F0.7BiS2 sample. The Arrhenius equation is used to calculate the thermally activated flux flow (TAFF) activation energy (U 0) for a NdO0.3F0.7BiS2 sample, which is 61.64 meV in 0.02Tesla field. Hall Effect measurements show that the electron charge carriers are the dominating ones throughout the studied temperature range of 300 K–2 K.