MICROWAVE CONDUCTIVITY OF THIN

The microwave response of a thin lm of high temperature superconductor YBa2Cu3O7− was measured for a wide region of temperatures and magnetic elds. From the measured complex frequency shift, the complex conductivity was calcu-lated. The model for eective conductivity in the mixed state was tted to the complex conductivity data and the values of upper critical elds Bc2(T) and de-pinning frequencies!0(T) have been obtained as tted parameters