X-ray photoelectron spectroscopy, Magnetotransport and Magnetization study of Nb2PdS5 superconductor

TL;DR

This study comprehensively investigates the structural, electronic, and superconducting properties of Nb2PdS5, revealing its robust high-field superconductivity, multiband behavior, and vortex pinning mechanisms through various experimental techniques.

Contribution

It provides new insights into the high-field robustness, multiband superconductivity, and vortex pinning characteristics of Nb2PdS5, expanding understanding of this superconductor's properties.

Findings

Superconductivity persists beyond the Pauli limit at high magnetic fields.

Resistivity follows Arrhenius behavior with decreasing activation energy at higher fields.

Evidence of multiband superconductivity and vortex pinning mechanisms.

Abstract

In the present report, we investigate various properties of the Nb2PdS5 superconductor. Scanning electron microscopy displayed slabs like laminar growth of Nb2PdS5while X-ray photoelectron spectroscopy exhibited the hybridization of Sulphur (2p) with both Palladium (3d)and Niobium (3d). High field (140kOe) magneto-transport measurements revealed that superconductivity (Tc onset =7K and Tc R = 0 = 6.2K) of the studied Nb2PdS5material is quite robust against magnetic field with the upper critical field (Hc2) outside the Pauli paramagnetic limit. Thermally activated flux flow (TAFF) of the compound showed that resistivity curves follow Arrhenius behaviour. The activation energy for Nb2PdS5 is found to decrease from 15.15meV at 10kOe to 2.35meV at 140kOe. Seemingly, the single vortex pinning is dominant in low field regions, while collective pinning is dominant in high field region. The temperature dependence of AC susceptibility confirmed the Tc at 6K, further varying amplitude and frequency showed well coupled granular nature of superconductivity. The lower critical field (Hc1) is extracted from DC magnetisation measurements at various T below Tc. It is found that Hc1(T) of Nb2PdS5 material seemingly follows the multiband nature of superconductivity.