NONBOLOMETRIC MICROWAVE RESPONSE OF A GRANULAR BI(PB)SRCACUO THIN-FILM

The response of a granular superconducting Bi(Pb)SrCaCuO thin film meander pattern to radiation from a 35GHz Gunn diode microwave generator was studied. The dependence of the response on film temperature, DC bias current, chopping frequency, and DC magnetic field was measured. Experimental results show that the response was non-bolometric in origin and was decreased by applying a DC magnetic field parallel to the c-axes of the grains. The mechanism of the non-bolometric microwave response is presumed to be due to microwave absorption by Josephson-type weak links embedded in the specimen. © 1993