Superconducting and magnetic properties of HgBa2Ca3Cu4O10+delta, CuBa2Ca3Cu4O10+delta, and B0.6C0.4(Sr0.25Ba0.75)(2)Ca2Cu3O9 superconductors with T-c above 115 K

摘要

We report the experimental results on the reversible magnetizations of the four-layer compounds HgBa2Ca3Cu4O10+delta (T-c similar or equal to 125 K) and CuBa2Ca3Cu4O10+delta (T-c similar or equal to 117 K), and the three-layer compound B0.6C0.4 (Sr0.25Ba0.75)(2)Ca2Cu3O9 (T-c similar or equal to 119 K). The magnetizations were analyzed using the Hao-Clem model and the high-field scaling law. From these analyses, we obtained various thermodynamic parameters such as the penetration depth and the critical fields, and clarified the dimensional nature of the superconductors. Even though the structures look similar, the physical properties of these compounds are quite different. We will discuss the correlation between the transition temperature and the interlayer coupling (or the carrier concentration within the CuO2 plane). [References: 17]