H. Jiang et al., MEASUREMENTS OF ANISOTROPIC CHARACTERISTIC LENGTHS IN YBCO FILMS AT MICROWAVE-FREQUENCIES, Journal of applied physics, 73(10), 1993, pp. 5865-5867
We used microwave self-resonant and magnetically modulated microwave a
bsorption techniques to measure the London penetration depth, lambda,
and coherence length, xi, in the direction parallel and perpendicular
to the a-b plane of YBCO films. We found that both lambda and xi were
anisotropic; it appeared that the value of lambda(parallel-to) (0) was
about 1800 angstrom and lambda(perpendicular-to) (86.5) about 26 000
angstrom, where lambda(parallel-to) is the penetration depth for the a
pplied microwave electric field parallel and lambda(perpendicular-to)
perpendicular to the film plane (c-axis is perpendicular to the film p
lane). We deduced xi(parallel-to) to be equal to 129 angstrom and ix(p
erpendicular-to) 40 angstrom at 86.5 K. The anisotropy factor y we det
ermined to be about 3.