Robust superconductivity with large upper critical field in Nb2PdS5

We report synthesis, structural details, and complete superconducting characterization of very recently discovered [Q. Zhang, Sci. Rep. 3, 1446 (2013)] Nb2PdS5 new superconductor. The synthesized compound is crystallized in monoclinic structure with C2/m (#12) space group. Bulk superconductivity is seen in both ac/dc magnetic susceptibility and electrical resistivity measurements with superconducting transition temperature (Tc) at 6 K. The upper critical field (Hc2) being estimated from high field magneto-transport [ρ(T)H] measurements is above 240 kOe. The estimated Hc2(0) is clearly above the Pauli paramagnetic limit of ∼1.84Tc. Heat capacity (Cp) measurements show clear transition with well defined peak at Tc, but with lower jump than as expected for a Bardeen–Cooper–Schrieffer type superconductor. The Sommerfeld constant (γ) and Debye temperature (ΘD) as determined from low temperature fitting of CP(T) data are 32 mJ/mole-K2 and 263 K, respectively. Hall coefficients and resistivity in conjugation with electronic heat capacity indicates multiple gap superconductivity signatures in Nb2PdS5. We also studied the impact of hydrostatic pressure (0–1.97 Gpa) on superconductivity of Nb2PdS5 and found nearly no change in Tc for the given pressure range.