INTERGRAIN MAGNETIZATION IN HIGH-TEMPERATURE SUPERCONDUCTORS

The results of intergrain magnetization calculations in high-temperatu re superconductors in a critical state model with the generalized expr ession for the critical current density J(c) = alpha(0) (1 - T/T-c)(q) /(B-0 + \B\)(beta) are presented. The temperature and field dependent local fields, magnetic loops and ac susceptibility have been calculate d. The procedure of determining parameters of pinning centres is also discussed. The experimental data of temperature dependences of fundame ntal ac susceptibility measured with various ac field amplitudes are c ompared with the calculated ones for a ceramic sample of YBa2Cu3O7-del ta.