Superconductivity with extremely large upper critical fields in Nb2Pd0.81S5
Here, we report the discovery of superconductivity in a new transition metal-chalcogenide compound, i.e. Nb2Pd0.81S5, with a transition temperature Tc ≅ 6.6 K. Despite its relatively low Tc, it displays remarkably high and anisotropic superconducting upper critical fields, e.g. μ0Hc2 (T → 0 K) > 37 T for fields applied along the crystallographic b-axis. For a field applied perpendicularly to the b-axis, μ0Hc2 shows a linear dependence in temperature which coupled to a temperature-dependent anisotropy of the upper critical fields, suggests that Nb2Pd0.81S5 is a multi-band superconductor. This is consistent with band structure calculations which reveal nearly cylindrical and quasi-one-dimensional Fermi surface sheets having hole and electron character, respectively. The static spin susceptibility as calculated through the random phase approximation, reveals strong peaks suggesting proximity to a magnetic state and therefore the possibility of unconventional superconductivity.
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Zhang, Qiu, Gang Li, Daniel Rhodes, Andhika Kiswandhi, T. Besara, B. Zeng, J. Sun, T. Siegrist, M. D. Johannes, and L. Balicas. "Superconductivity with extremely large upper critical fields in Nb 2 Pd 0.81 S 5." Scientific reports 3, no. 1 (2013): 1-7.