Susceptibility and magnetization characterization of bulk high Tcsuperconductors: scaling length and critical current densities

Low field DC and AC susceptibility (swept temperature) and magnetization (swept field) are routinely used to characterize bulk samples of high Tc superconducting materials. More information can be obtained by extending these techniques, for example, by adding a DC offset field in the AC susceptibility measurements and by making magnetization measurements for several different cycles of the applied field. The relationships between the critical current and its scaling length are developed with respect to these experimental techniques.