Single gap s-wave superconductivity in Nb2PdS5

Superconducting order parameter and its symmetry are important parameters towards deciphering the pairing mechanism in newly discovered superconducting systems. We report a study on penetration depth measurement on Nb2PdS5 that has recently been reported with extremely high upper critical field with possible triplet pairing mechanism. Our data show that at low temperatures the change in penetration depth Delta lambda is best fitted with BCS s-wave model for single gap with zero-temperature value of the superconducting energy gap Delta(0) = 1.05 meV, corresponding to the ratio 2 Delta(0)/k(B)T(c) = 3.9 +/- 0.18. The superfluid density in the entire temperature range is well described by single gap with gap ratio 2 Delta(0)/k(B)T(c) = 4.1 +/- 0.13 for lambda(0) = 225 nm. (C) 2016 Elsevier B.V. All rights reserved.