AC losses in high-temperature superconductors

Intergranular and intragranular AC losses in the superconducting state of ceramic high-temperature superconductors are calculated using a critical state model for the intergranular loss contribution that is similar to that of Y.B. Kim et al. (1963) and the model of C.P. Bean (1962) for the intragranular loss. Good agreement with experimental data over a magnetic field range of 10/sup -4/ T to 10 T is achieved. The effects of sample size, average grain size, and temperature are investigated. In addition, the influence of a DC field on the intergranular AC loss is discussed.