A. Pertile et al., MODEL FOR LOW-FIELD MICROWAVE-ABSORPTION IN GRANULAR TYPE-II SUPERCONDUCTORS, Physical review. B, Condensed matter, 52(21), 1995, pp. 15475-15478
A model of microwave absorption in superconductors is proposed in whic
h the applied microwave field interacts with the fluxons in the surfac
e layers of the superconducting grains. The flux in these surface laye
rs is mainly reentrant and antiparallel to the flux trapped inside. Me
asurements are reported of low-field microwave absorption in the YBa2C
u3O7-delta superconductor carried out under field-cooling and zero-fie
ld-cooling conditions in the temperature range from 5 to 80 K, and the
y are well explained by this model.