Superconductivity of Ni-doping 2H–TaS2

The superconductivity of 2H–NixTaS2 single crystals with Ni-doping content of 0⩽x⩽0.08 is investigated. Compared with the temperature dependence of resistivity ρ(T) curve of un-doped 2H–TaS2 with charge density wave (CDW) transition (TCDW=78K), no sign of CDW is observed for Ni-doping sample NixTaS2, meaning the suppression of CDW caused by Ni-doping. The increase of superconducting critical temperature TC caused by Ni-doping is observed and the optimal Ni-doping content corresponding to the maximum zero resistance temperature TCzeromax=4.15K is x=0.04. The superconductivity of Ni0.04TaS2 is investigated in detail. The obtained superconducting parameters indicated that Ni0.04TaS2 is an intermediate coupling anisotropic type-II superconductor with anisotropy ratio γ=Hc2ab(T)/Hc2c(T)≈3.58.