Internal friction related to carriers in Hg-system superconductors

Internal friction (Q(-1)) results of Hg-based cuprate superconductors with 1201 (T-c = 94 K) and 1223 (T-c = 117 K) phases are reported. The internal friction reveals a plateau (Q(p)(-1)) above T-c and drops obviously below T-c with the turning point located at T-c. The structures and Q(-1) results of Hg-based superconductors are similar to those of Bi- and Tl-based ones. We expect that Q(p)(-1) is also closely related to the carriers and the drop of Q(-1) below T-c is associated with the superconducting condensation in Hg-based superconductors. Taking account of the smearing of the superconducting gap structure and using a modified BCS transition rate of quasiparticles, the superconducting gap Delta and damping rate Gamma are also obtained.