The ac loss near the glass-liquid transition temperature in high-T_c superconductors- an extended bean model

摘要

The ac loss in high-T_c superconductorsnear the glass-liquid transition T_g is studied numericallyand theoretically. It is found that the ac loss in a slab undera dc bias magnetic field depends remarkably on the angularfrequency, #omega#, which cannot be described by theusual critical state model using the critical current densityJ_C defined with the electric field criterion. However, it isshown that the ac loss including the flux flow loss isdescribed quantitatively by the well known expression basedon the Bean critical state model, where J_C is replaced bythe effective critical current density J_ce (#omega#) Theapplicability of the present expression is also discussed.