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 Tc≃108K. We obtained thermodynamic parameters, such as the penetration depth [λab(0)] and the coherence length [ξab(0)] from the thermodynamic critical field [Hc] 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 (Tc) of the Hg1245 did not increase as compared to the Hg1234. The expected increase of Tc for the material with the more CuO2 planes was not achieved because of the insufficient doping of the Cooper pairs while adding CuO2 planes.