Investigation of normal and superconducting states in noncentrosymmetric Re24Ti5
Journal
Superconductor Science and Technology
Journal Volume
26
Journal Issue
5
Pages
1-6
Date Issued
2013
Author(s)
Abstract
We report a detailed characterization of the noncentrosymmetric superconductor Re24Ti5 using powder x-ray diffraction (XRD), magnetic susceptibility, electrical resistivity, thermal conductivity, Seebeck coefficient, and specific heat measurements. Rietveld refinement of powder XRD data confirms that Re24Ti5 crystallizes in the α-Mn structure. All measured quantities demonstrate a bulk superconducting transition at Tc = 5.8 K. Our low-temperature specific heat data measured down to 0.5 K yield a Sommerfeld coefficient γ = 111.8 mJ mol-1 K-2, which implies a high density of states at the Fermi level. Moreover, the electronic specific heat in the superconducting state was found to obey a typical s-wave expression, revealing a single gap Δ/kB = 10.6 K. This value gives a ratio of 2Δ/k BTc = 3.68, higher than the value of 3.5 predicted from BCS theory. On this basis, we conclude that the noncentrosymmetric Re 24Ti5 compound can be characterized as a moderately coupled BCS-type superconductor. Furthermore, the obtained parameters from the present study of Re24Ti5 were compared to those of the isostructural compound Re23.8Nb5.2, indicating the similarity between both systems. © 2013 IOP Publishing Ltd.
SDGs
Type
journal article