T c vs n Relationship for Multilayered High- T c Superconductors

We have proposed a T c vs n relationship for multilayered high- T c superconductors from the analysis of HgBa 2 Ca n -1 Cu n O y grain-aligned samples containing n =6 to 16 phases. The sample showed a large and sharp superconducting transition at 105 K in its susceptibility vs temperature curve. This means that multilayered HgBa 2 Ca n -1 Cu n O y can maintain a high T c at least up to n ≈16, otherwise many transitions would have been observed. It is generally believed that the highest T c decreases with n for n ≥4–5 for multilayered superconductors. We conclude that the highest T c is almost constant above about n =5 if the factors reducing T c , such as disorder, are eliminated for multilayered superconductors. This behavior can be explained using an inhomogeneous charge distribution model in multilayered cuprates.