Peak effect in a superconducting DyBa2Cu3O7-delta film at microwave frequencies - art. no. 180502

We report the observation of a peak in the microwave (9.55 GHz) surface res istance in an epitaxial DyBa2Cu3O7-delta superconducting film in magnetic f ields (parallel to the c axis) ranging between 0.2 to 0.9 T. Such a peak is absent in the measurements done in zero held. The temperature and held dep endence of the peak suggests that this peak could be associated with the pe ak effect (PE) phenomenon reflecting the order-disorder transformation in t he flux-line lattice (FLL). A strong frequency dependence of the PE is obse rved close to the depinning frequency of the FLL.