Modeling of the microwave characteristics of layered superconductor/ferromagnetic structures

Microwave (MW) characteristics of tangentially magnetized double layer structures consisting of a high temperature superconducting (HTS) and a conductive ferromagnetic (FM) manganite films (with the parameters similar to those of HTS YBa2Cu3O7 (YBCO) and FM La0.7Sr0.3MnO3 (LSMO) films) were modeled with respect to the linear polarized planar transverse electromagnetic wave incident perpendicularly to the FM film surface. The surface impedance of such a structure is characterized with the peculiarities caused by the HTS transition and the ferromagnetic resonance (FMR). The MW losses caused by the conductivity of the FM manganite film in double layer FM/HTS structures decrease drastically at temperatures T lower than the critical one TC and FMR losses become dominant: in this case the peculiarity of the surface impedance caused by FMR can be observed clearly in the structure. A strong magnetic field dependence of the surface resistance can be observed in manganite/HTS structures at T < TC due to the FMR effect.