Superconducting properties of the misfit-layer compound (SnSe)_1.18(TiSe₂)₂

We report the superconducting properties in the misfit layered compound (SnSe)_1.18(TiSe₂)₂ with critical temperature 3.3 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 of the compound is about 1.55 which is obtained from the superconducting parameters of the zero-temperature-limit upper critical field and coherence length using the Werthamer-Helfand-Hohenberg (WHH) formula. The small values of specific heat jump and electron-phonon coupling constant 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. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)