Sk. Remillard et al., THE MICROWAVE SURFACE IMPEDANCE OF GRANULAR HIGH-T(C) SUPERCONDUCTORSIN DC MAGNETIC-FIELDS - ITS RELATIONSHIP TO FREQUENCY-DEPENDENCE, Journal of applied physics, 75(8), 1994, pp. 4103-4108
The surface impedance of bulk and thick film granular high temperature
superconductors has been studied. The static magnetic field, temperat
ure, and frequency dependence of the surface ce have been analyzed in
terms of the weakly coupled grain model. Accurate quantitative predict
ions of the frequency dependence of the surface resistance are made us
ing this model. The model also quantitatively accounts for the negativ
e magnetic field coefficient of the effective rf penetration depth. Th
e rf penetration depth is a maximum when the ratio of penetration dept
h to skin depth is 0.930.