Magnetization Measurements of Hard Superconductors under Dissipative Transport

The hysteretic magnetic flux dynamics of ceramic type-II superconductors under superimposed transport current cycles has been investigated.

Field cooled and zero field cooled experiments were carried-out on polycrystalline YBa₂Cu₃O_7-x cylinders by using both temperature and applied field control, to drive the sample into the semi-reversible granular regime. The transport current magnitude was near and above the dissipative threshold. The interplay between shielding and transport due to vortex-pinning interactions, equilibrium magnetization effects, and diamagnetic/paramagnetic relaxation phenomena are shown to play an important role in the range of practical applications.