Determination of field and temperature dependences of the intergrain critical current density J(sub c)(sup (omega))(H,T) in high-temperature superconductors

摘要

The determination of field and temperature dependences of the intergrain critical current density J(sub c)(sup (omega))(H,T) in high-temperature superconductors by using the field and temperature dependent ac-susceptibility is presented. The J(sub c)(sup (omega))(H,T) of Bi(sub 1.65)Pb(sub 0.35)Sr(sub 2)Ca(sub 2)Cu(sub 3)O(sub 10+(delta)) and YBa(sub 2)Cu(sub 3)O(sub 7-(delta))-ceramics as well as a thick film YBa(sub 2)Cu(sub 3)O(sub 7-(delta)): 8% Ag are estimated by this method. It is shown that the main mechanism limiting J(sub c)(sup (omega)) is decoupling superconducting grains coupled by normal metal layers (S-N-S type weak links). 13 refs., 4 figs., 1 tab. (Atomindex citation 27:009847)