SIZE EFFECT IN HIGH-TEMPERATURE SUPERCONDUCTORS AT UNILATERAL ELECTROMAGNETIC-EXCITATION

The size effect in a high-T-c superconducting plate at unilateral elec tromagnetic excitation is theoretically studied. This effect manifests itself, for example, in the temperature dependences of the surface im pedance and absorptivity. It is established that the plate absorptivit y versus temperature has always a maximum independently on the dielect ric permeability of its substrate. At the same time the size effect in the surface resistance is quite sensitive to the substrate properties . Calculations are carried out within the frame of the theory of therm ally assisted flux flow (TAFF) using only one parameter of the superco nductor, namely, the temperature-dependent effective conductivity sigm a.