Superconducting properties of the misfit-layer compound (SnSe)1.18(TiSe2)2

Abstract

We report the superconducting properties in the misfit layered compound (SnSe)1.18 (TiSe2)2 with critical temperature Tc3.3 K at ambient pressure. Even though this compound is a polycrystalline compound, it shows anisotropic properties from the X-ray diffraction, electrical transport, magnetization, and high-resolution transmission electron microscopy measurements. The anisotropic parameter γHc2 of the compound is about 1.55 which is obtained from the superconducting parameters of the zero-temperature-limit upper critical field Hc2(0) and coherence length ξ using the Werthamer–Helfand–Hohenberg (WHH) formula. The small values of specific heat jump ΔC/γTc and electron–phonon coupling constant γe-ph indicate a weak-coupling BCS superconductor. The critical current density is exceptionally high (8000 A cm−2) compared to other misfit-layer superconductors. Isothermal hysteresis of magnetization, and critical current density (inset), with respect to the applied magnetic field for various temperatures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim