ISSN:
1573-7357
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We measure the diamagnetic response of YBa 2 Cu 3 O y A x (A=Cl, F, H) ceramics. We obtain low-field effective penetration depths λ of a few 10 μm, first flux-penetration field H1 distinguishable from the volume penetration field HC1 and two characteristic temperatures Ts and Tc, Tc〈Ts, defined by the onset of the real and imaginary parts of the susceptibility, respectively. H 1 (T) goes to zero as a power law H 1 (T, x)=H 1 (0, x) (T−T/Tc) 2.7 near TC. From the values of λ and H 1 we infer the correlation length ξ at T=4.2 K. A large range of values for ξ(4.2) suggests that chemical disorder plays an essential role in the phenomenology of cuprates. We find λ(4.2)∼H 1 (4.2) −1/3 . This, and the power law ξ(4.2)∼H 1 (4.2) −2/3 result from the scaling properties of a phase transition governed by disorder.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1021763626966