Superconductivity in Sn intercalated 2H-TaS₂

One of the most effective technique to tune the physical properties of layered transition metal dichalcogenides is the metal intercalation approach. Successful Sn intercalation into the van der Waals (vdW) layers of 2H-TaS₂ was achieved by solid state reactions which led to formation of polycrystalline SnTaS₂. SnTaS₂ crystallizes into a centrosymmetric hexagonal structure (space group: P6₃/mmc) where Ta occupies the trigonal-prismatic position coordinated with S atoms and Sn accommodates the octahedral site, create alternative layers of TaS₂ and Sn. The charge density wave (CDW) in 2H-TaS₂ got totally suppressed due to the intercalation, leading to a superconducting phase with T_c~ 2.8 K. Superconductivity was further confirmed from the Meissner effect observed in the DC magnetic susceptibility. The characteristic upper and lower critical fields are found to be μ₀H_c2(0) = 1458 Oe and μ₀H_c1(0) = 45.5 Oe respectively. From the superconducting coherence length ξ_GL(0) = 47.5 nm and the penetration depth λ_GL(0) = 243 nm, the Ginzburg-Landau parameter is determined to be κ = 5.12 which indicates that SnTaS₂ is a type-II superconductor with the thermodynamic critical field value μ₀H_c(0) = 202 Oe.