Thermodynamic properties of five-layered HgBa2Ca4Cu5O12+y from equilibrium magnetization

By using the Hao–Clem model, we analyzed the equilibrium magnetization of the grain-aligned HgBa2Ca4Cu5O12+y (Hg1245) with T c ≃ 108 K . We obtained thermodynamic parameters, such as the penetration depth [ λ ab ( 0 ) ] and the coherence length [ ξ ab ( 0 ) ] from the thermodynamic critical field [ H c ] and the Ginzburg–Landau parameter [ κ ] . Compared to the four layered superconductor HgBa2Ca3Cu4O10+y (Hg1234), the obtained penetration depth was slightly increased indicating that the Cooper pair density of Hg1245 was decreased, which was one of the reasons why the transition temperature ( T c ) of the Hg1245 did not increase as compared to the Hg1234. The expected increase of T c for the material with the more CuO2 planes was not achieved because of the insufficient doping of the Cooper pairs while adding CuO2 planes.