R. Swarup et al., EFFECT OF SAMPLE DENSITY ON MAGNETIC PENETRATION DEPTH IN YBACUO CERAMIC SUPERCONDUCTORS, Journal of superconductivity, 8(3), 1995, pp. 361-364
We have measured magnetic penetration depth lambda(0) of high-T-c YBCO
samples of different density by the cavity resonant frequency shift m
ethod at 10, 16.65, and 22.3 GHz microwave frequencies. The value of l
ambda(0) at 10 GHz is found to decrease from 5850 Angstrom to 2550 Ang
strom as the density of the sample increases from 4.4 to 5.3 g/cm(3).
The results of the frequency response of the penetration depth show a
fairly constant value of lambda(0) for all the three samples in the fr
equency range 10-22.3 GHz. The wide variation observed in the value of
lambda(0) for different density samples has been explained in terms o
f varying Josephson coupling strength in these ceramics.