NON-EQUILIBRIUM MICROWAVE RESPONSE OF Yba 2 Cu 3 O 7-δ GRANULAR THIN FILMS UNDER MAGNETIC FIELDS

Microwave responses of YBa2Cu3O7-δ (YBCO) granular film have been studied at the microwave frequency of 30.5 GHz. In the absence of a magnetic field the dependence of a normal microwave response on the bias current is observed at a temperature close to Tc. When a magnetic field ranged from 5.0 mT to 33.0 mT is applied, the responses broaden and shift toward a lower temperature. In the superconducting state, the responses were found to be highly dependent on the magnetic field. For the current equal to 5.0 mA and a magnetic field above 17.0 mT the response increases and did not vanish even at a very low temperature, the fact is believed to be correlated to the anisotropic character of the structure.