NON-EQUILIBRIUM MICROWAVE RESPONSE OF Yba₂Cu₃O_7-\delta GRANULAR THIN FILMS UNDER MAGNETIC FIELDS

Microwave responses of YBa₂Cu₃O_7-\delta(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 T_c. 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 5.0mA and a magnetic field above 17.0mT 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.