Possible indicators for low dimensional superconductivity in the quasi-1D carbide Sc3CoC4

TL;DR

This paper investigates the low-dimensional superconductivity in the quasi-1D carbide Sc3CoC4, revealing its type II superconducting nature and comparing its unique features with other low-dimensional superconductors.

Contribution

It identifies Sc3CoC4 as a new candidate for quasi-1D superconductivity and analyzes its unconventional superconducting properties.

Findings

Sc3CoC4 is a type II superconductor with {}_L  9750 Å and {}_GL  187 Å.

Superconductivity appears below 4.5K with unusual temperature dependence of critical parameters.

Comparison with other low-dimensional superconductors highlights unique features of Sc3CoC4.

Abstract

The transition metal carbide Sc3CoC4 consists of a quasi-one-dimensional (1D) structure with [CoC4]$_{\inft}$ polyanionic chains embedded in a scandium matrix. At ambient temperatures Sc3CoC4 displays metallic behavior. At lower temperatures, however, charge density wave formation has been observed around 143K which is followed by a structural phase transition at 72K. Below T^onset_c = 4.5K the polycrystalline sample becomes superconductive. From Hc1(0) and Hc2(0) values we could estimate the London penetration depth ({\lambda}_L ~= 9750 Angstroem) and the Ginsburg-Landau (GL) coherence length ({\xi}_GL ~= 187 Angstroem). The resulting GL-parameter ({\kappa} ~= 52) classifies Sc3CoC4 as a type II superconductor. Here we compare the puzzling superconducting features of Sc3CoC4, such as the unusual temperature dependence i) of the specific heat anomaly and ii) of the upper critical field H_c2(T) at T_c, and iii) the magnetic hysteresis curve, with various related low dimensional superconductors: e.g., the quasi-1D superconductor (SN)_x or the 2D transition-metal dichalcogenides. Our results identify Sc3CoC4 as a new candidate for a quasi-1D superconductor.